I was impressed by Thomas Gibson. I liked him as Greg in Dharma & Greg, although I got the impression that as Greg, Gibson just kind of acted himself. He may still be acting himself in Criminal Minds, but he achieved a darker, less friendly-guy persona without too much difficulty.
The one bewildering thing about the show is the enormous cast. There's nearly seven major players wandering around the screen at all times. Kind of like Boston Legal with the difference that Boston Legal is really just a restoration comedy between Shatner and Spade with a supporting cast. Criminal Minds looks like being an ensemble cast.
Ensemble is okay to a point, but you still need a reference point (like Mandy Pantakin). I think this is the trouble with CSI:NY. Gary Sinise (who I admire) is so retiring, he doesn't serve (as Caruso does) as a focal point. And then there is Dr. House who most certainly does. And the (obviously) canon couple on Bones (watching Bones is just a bit like watching the canon couple in the Thin Man movies).
Speaking of House and Bones, I would like to thank Tuesday night for giving me the chuckles TWICE: in Bones, the line (these are approximate), "What? You wanted to listen to the crazy psycho speech?" and Wilson's line on House, "Now that is superior television," while Forman nods agreement.