1.
Krista Allen as Kristy Hopkins - "Pilot" - 2000
Krista Allen played prostitute Kristy Hopkins in three episodes of CSI in it's premiere season, beginning with its pilot!. Don't get too attached. She unwittingly makes a connection with Nick, and after sleeping with him in CSI Season 1 Episode 13 becomes the subject of a murder investigation. Oh no!!
2.
Milo Ventimiglia as Bobby Taylor - "Friends & Lovers" - 2000
Milo Ventimiglia turns up as a suspect and eventual killer of his best friend in this heartbreaking performance on "Friends & Lovers," CSI Season 1 Episode 5. Look at those tears!
3.
Dakota Fanning as Brenda Collins - "Blood Drops" - 2000
A teeny weeny little Dakota Fanning was at the heart of a family massacre story on "Blood Drops," CSI Season 1 Episode 7, when she guest starred as Brenda Collins in 2000. A sad tale of murder and sexual abuse, her face sure belies the tale!
4.
Shawn Christian as Patrick Haynes / Chad Matthews - "Table Stakes" - 2001
Hey! Days of Our Lives star Shawn Christian got down and dirty when his sister (who he was passing off as his wife) killed a woman on "Table Stakes," CSI Season 1 Episode 15. Whoopsies!
5.
Aldis Hodge as Tony Thorpe - "Too Tough to Die" - 2001
Aldis Hodge played Tony Thorpe in CSI Season 1 Episode 16, "Too Tough to Die," a role he'd later reprise in 2008. Talk about a long wait to return! Pretty cool though. His character was a murderer and rapist, who was used by the victim's husband years later to justify pulling the plug on his brain-dead wife.
6.
Brigid Branaugh as Tammy Felton - "Face Lift" - 2001
Bridgid Branaugh was on two episodes of CSI. In the first, "Face Lift," CSI Season 1 Episode 17, she's discovered to have been a woman who was kidnapped as a small child and raised as someone different. In the next, CSI Season 2 Episode 9, "And Then There Were None," she's murdered. Multiple episodes of CSI are bad on guest stars!
7.
Brian McNamara as Steven Anderson - "Gentle, Gentle" - 2001
Brian McNamara guest starred as a father protecting his family from a tragic lie in CSI Season 1 Episode 19, "Gentle, Gentle." If you can imagine the worst possible circumstances happening to a family by accident? Yep, this would suit.
8.
Rainn Wilson as Guy in Supermarket - "Strip Strangler" - 2001
While fellow guest star Michael Cerveris was getting away with murder, guy in supermarket Rainn Wilson was pretending to make a pass on Sara to steal her wallet in the first season finale of CSI titled "Strip Strangler." See his shifty eyes? He was getting ready to move!
9.
Brenda Strong as Dr. Leigh Sapien, "Overload," 2001
Brenda Strong was Dr. Leigh Sapien in CSI Season 2 Episode 3, "Overload." The good doctor is a psychiatrist who practices rebirthing and it goes terribly wrong on a 14-year-old boy. Do these sessions ever go right in these situations?
10.
Jeremy Renner as Roger Jennings - "Alter Boys" - 2001
Before Jeremy Renner was doing the impossible beside Tom Cruise, he was a pizza boy accused of murder on CSI Season 2 Episode 6, "Alter Boys." Did he really do the crime? Watch to find out.
11.
Kelly Rowan as Eileen Nelson - "Slaves of Las Vegas" - 2001
Kelly Rowan guest starred in the first episode of CSI to show brief nudity and also the first to feature Melinda Clarke as Lady Heather, who will reprise her role in the series finale. Not much of a nod, but here she is, nonetheless!
12.
Marcia Cross as Julia Fairmont - "Organ Grinder" - 2001
Marcia Cross was in CSI Season 2 Episode 11, "Organ Grinder" as part of a killer duo. She's the second of the Desperate Housewives to hit this slideshow, and was the wife of the victim, a secretary and murderer!
13.
Jason Beghe as Russ Bradley - "Burden of Proof" - 2002
On CSI Season 2 Episode 15 Jason Beghe guest starred as Russ Bradley. THE KILLER!!! Of course the big gun on Chicago PD was playing a killer in 2002! Sadly, that isn't the worst crime he committed. And? No deal.
14.
Zachary Quinto as Mitchell Sullivan - "Anatomy of a Lye" - 2002
Zachary Quinto guest starred as a dude working in a chop shop in CSI Season 2 Episode 21, "Anatomy of a Lye." How adorable does he look as that kind of dude? LOL
15.
Mark Sheppard as Rod Darling - "The Hunger Artist" - 2002
Mark Sheppard guest starred as Rod Darling on CSI Season 2 Episode 23, "The Hunger Artist," and isn't he just darling? This was the episode in which Grissom started experiencing hearing problems.
16.
Ian Somerhalder as Tony Del Nagro - "Revenge is Best Served Cold" - 2002
The CW is represented going out of Season 2 and swinging into Season 3 as Ian Somerhalder guest stars in CSI Season 3 Episode 1 as Tony Del Nagro (what a name!), "Revenge is Best Served Cold." You think he's serving the revenge? You really think I'd tell you a reveal on a guest star this big? Tsk, tsk.
17.
Chad Michael Murray as Tom Haviland - "The Accused is Entitled" - 2002
Because the better looking the guest star, well, the better, CSI Season 3 Episode 2, "The Accused is Entitled" featured Chad Michael Murray as the entitled accused, a skanky (and hot) movie star. The Wallflowers (remember them?) also made an appearance.
18.
Niecy Nash as Snuff Film Processor - "Snuff" - 2002
Niecy Nash has come a long way from her guest starring role as a no-named snuff film processor on CSI Season 3 Episode 8, "Snuff." She's now a rent-a-cop on Scream Queens!
19.
Evan Rachel Wood as Nora Easton - "Got Murder?" - 2003
Evan Rachel Wood made an appearance in CSI Season 3 Episode 12, "Got Murder?" as Nora Easton. She's still a kid!
20.
Pauley Perrette as Candeece / Pink Hair ' "Lady Heather's Box" - 2003
CSI Season 3 Episode 15, "Lady Heather's Box" brings with it Pauley Perrette as Candeece / Pink Hair. She seems to be just a little bit typecast as the tough yet soft chick, doesn't she?
21.
Katherine LaNasa as Ginger - "Precious Metal" - 2003
Satisfaction's Katherine LaNasa guest starred as Ginger on CSI Season 3 Episode 18, "Precious Metal." She comes off a little like Rizzo from Grease in this one.
22.
Willie Garson as Bud Simmons/Sexy Kitty - "Fur and Loathing" - 2003
Willie Garson headed to CSI Season 4 Episode 5, "Fur and Loathing" to play Bud Simmons/Sexy Kitty. What?! Methinks this furry ain't going by a CB handle! Did he feel safe enough to kill in there?
23.
T. R. Knight as Zero Adams - "XX" - 2004
T. R. Knight as Zero Adams in CSI Season 4 Episode 17, "XX" wasn't the only guest star, as Gina Torres also starred as a prison warden.
24.
Megan Follows as Beth Darian - "Bad to the Bone" - 2004
She was no queen when Megan Follows guest starred on CSI Season 4 Episode 18 as Beth Darian, but she's still royalty to us!
25.
Melissa Leo as Sybil Perez - "Harvest" - 2004
Oscar winner Melissa Leo was the mother of a murdered teenager on "Harvest," CSI Season 5 Episode 1. She's come a long way from these guest arcs!
26.
David Anders as Travis Watson - "Crow's Feet" - 2004
iZombie's David Anders showed up as a lab tech on CSI Season 5 Episode 4. He looks awfully serious, doesn't he?
27.
Seth Gabel as Gavin 'Rex' Layne - "Formalities" - 2004
Seth Gabel pops up as a possible drug dealer and murderer on CSI Season 5 Episode 7, "Formalities." He does something he does very well; acts entitles and like a total smartass.
28.
John Krasinski as Lyle Davis - "Who Shot Sherlock" - 2005
John Krasinski is involved in a case where he might have left a dude for dead after helping his car veer off the road on CSI Season 5 Episode 11. Whoops!
29.
Misha Collins as Vlad - "Nesting Dolls" - 2005
Before he was the go-to angel on Supernatural, Misha Collins was doing blink and you miss them roles on shows like this, seen here on CSI Season 5 Episode 13.
30.
Eric Winter as Julian Harper - "Room Service" - 2005
Eric Winter guest starred as an up and coming movie star and VICTIM OF MURDER in CSI Season 6 Episode 2! Who could be so horrible to kill such a pretty face?
31.
Silas Weir Mitchell as Willie Angel - "Room Service" - 2005
What? A two-fer? Yep, because this Grimm guy was a suspect in the murder of Eric Winter's character. Did he do it or was he just a thief stuck in the room watcing Winter boink a woman? Hmmmm...
32.
Seamus Dever as Adam Gilford - "Bite Me" - 2005
Look who made an appearance in CSI Season 6 Episode 5! Castle's own Seamus Dever! This installment was about a woman who took to biting her male friends in the neck. Her nickname? Buffy. Of course.
33.
Kristin Bauer van Straten as Kenli Johnson - "Secrets and Flies" - 2005
When she wasn't the sultry and sexy Pam on True Blood, Kristin Bauer van Straten looks a little a different. Here she is as Kenli Johnson, a suspect for the murder of an adoptive mother on CSI Season 6 Episode 6, "Secrets and Flies."
34.
Faye Dunaway as Lois O'Neill - "Kiss Kiss, Bye Bye" - 2006
CSI Season 6 Episode 13 had a movie star in its midst as Faye Dunaway guest starred as Lois O'Neill, a socialite who published a tell-all book about old Las Vegas on "Kiss Kiss, Bye Bye."
35.
Taraji P. Henson as Christina - "I Like to Watch" - 2006
It's Cookie! Well, not exactly. It's Taraji P. Henson as Christina on CSI Season 6 Episode 17, "I Like to Watch." Her character was the victim of a terrible sexual assault, and she's strong enough to talk about it in detail.
36.
Kat Graham as Tisha - "Poppin' Tags" - 2006
Ian Somerhalder isn't the only Vampire Diary vet who can cry crocodile tears. Check out Kat Graham as Tisha in CSI Season 6 Episode 20, "Poppin' Tags." They have something else in common – they're both in the hot seat within the last quarter of their respective episodes!