I got rid of iChat and that's about it. I would get rid of iMovie as I only use Final Cut Pro and Motion and the like, but my friends in the lower production classes sometimes use it on my mac, so I keep it around.
On the other hand, I've installed Photoshop, ImageReady, GoLive, Flash, Fireworks, Dreamweaver, Final Cut Pro 5, LiveType 2, Motion 2, Shake 4, LimeWire, Office, Transmit, Firefox, AIM, Wolfenstein ET, Azureus, Cocktail, CandyBar, GMail notifier, Handbrake, MovieToGo, MacTheRipper, MRChat, and Toast.