Either the Dead or Phish... probably Phish, because I got into them first. I saw Umphrey's in B-more a while ago, and I thought they were very very unremarkable.
I miss Mikey too and never got to see them live with him playing. They're still good but not the same without him. umphrey's is a sound you need to hear more to become acclimated...it took me over a year...maybe I'm slow, but finally everything clicked and I got hooked. Maybe you won't, but keep listening (go to their website and get the podcasts) and maybe it'll happen for you too.
String Cheese Incident.... I kept seeing the fog machine clouds in the light and I kept forgetting music was playing. Sometimes I'll just alternate between focusing on the music and spazzing out while eyeballing the lighting/effects.
I can't pick just 3..........I like GD the best........KW, SCI, Phish, YMSB, Robert Randolph, anything with Les Claypool, especially Oysterhead....HBRSB, anything with Dawg, disco biscuits..........im gonna stop but thiers alot more.........thats just where my mind went first.