Doom 3 - I own it for Xbox so I didn't play the demo.
Psychonauts - I seriously was not looking forward to playing the demo but thought I would give it a try. I really liked the demo & the graphics are outstanding. The humor is actually funny. I normally dislike platformers but this one looks pretty good.
Darkwatch - I did not try the demo since b/c of the mentioned problems but the trailer looked pretty cool.
Pariah - A nothing special FPS.

Black Hawk Down looks like it could be pretty sweet. I look forward to seeing more about this one.
Conker - The "Current Affair" parody was actually pretty funny at times.
25 to Life - may be really cool or may really suck judging by the trailer. Hard to say.
Dead to Rights II - I never played the first one but this looks to be a Max Payne rip-off with a dog.
Lego Star Wars & Revenge of the Sith - looks interesting but then again, these are for the "new" trilogy.


BTW - RVP...I agree with you. Hiding demos is stupid...especially if they tell you they hid it on the back of the sleeve. Silly.