If you are looking for medium to high gain tones on the clean channel, check these out: MI Audio Crunch Box, Kaden Effects Brown Creeper, Fulltone OCD. I also use the much maligned Fulltone Distortion Pro (my primary pedal for leads), but many people seem to dislike it, so you may want to pass up that one unless you can try one before you buy.
The H.B.E. Big D was nice, but I found only one of the many settings to really be of use. The one sound I did like was inferior to both the Crunch Box and Brown Creeper. I like the Fulltone OCD by itself, but usually boost it with my Fulldrive 2 to add tightness and mids. Otherwise the OCD sounds a little too scooped live, and the bass can be overwhelming at times.
For low to medium gain tones, check out the Fulldrive 2 Mosfet (love mine, its like a swiss army knife for tone), or the MI Audio Blues Pro. The OCD can do lower gain tones as well, but I think it excels as a medium gain device or as a booster.