The List
From… TOW Frank, Jr.
Monica: So, Chandler... who's on your list?
Chandler: Uh, Kim Basinger, Cindy Crawford, Halle Berry, Yasmine Bleeth, and, ah, Jessica Rabbit.
Rachel: Now, you do realize that she's a cartoon... and way out of your league?
Chandler: I know, I know, I just always wondered if I could get her eyes to pop out of her head
Chandler knows that Jessica Rabbit is a cartoon. And truthfully he really has very little interest in a one-off sexual encounter with a cartoon. (Partly because he figures he would never make her eyes pop out, and also because he thinks he'd make a pretty boring cartoon).
But he can't tell anyone (not Janice, not Joey, not anyone) his number five (one).
Number five (one) doesn't meet the list criteria, anyway, even if she's just as unattainable and out of his league as an animated drawing with spectacular anatomy.
Janice won't consider Chandler's number five (one) a celebrity.
Monica Geller isn't a star to anyone except Chandler.