Although I still use D76 on occasion, I mostly have switched to Pyro-Cat HD for all my films. Pyrocat is very economical, lasts really well and gives a really nice combination of fine grain with good acutance. That said, if you just stuck to ID11 or D76 you wouldn't go wrong.
There are many here that will say to stick to one developer and really get to know it...that is not a bad philosophy...but I will always just give something new a go on occasion.