Thanks for all the great replies guys. =)
Saint.Panda: Well, it's hard to say what my preference is considering the SR-60 is the only decent pair of headphones I've ever owned. The SR-60s sound very good to my ears, not overly bright at all like some have mentioned, at least not from this Audigy playing high bitrate MP3s. In general, I think the single thing I notice the most is the low end bass (deepness and accuracy). As far as these Grados, the amount of bass is about right. Under no circumstance would I want less bass, but I suppose a bit more would be fine. The mids are usually good, but sometimes I've wished for a bit more detail and/or separation. The highs are definitely a strength of the Grados. I have no complaints there.
I mainly listen to New Age, Symphonic, Electronic music. I think I'd pick detail before soundstage, but it'd be nice to get both. As far as between "more aggressive and upfront" and "laid-back and smooth sound", I think more aggressive and upfront sounds better. I like my music musical and exciting.
So to sum up:
1. Deep, accurate bass (not overly boomy though) no less strong than the SR-60s.
2. Crisp mids. If there's one thing I've sometimes wished for, it's clearer mids.
3. Highly detailed, crystal clear highs. I think the highs are one of the biggest reasons I like the SR-60s. Now if everything else was that good....
I guess I want everything, dammit.
Jorg: I absolutely wouldn't be *able* to play games? It was my impression that I at least could, but the CPU utilization would be higher and the sound wouldn't be as good. Is it tough/possible to use two soundcards?