Now for a change talking about meaningful levels (i.e. levels that bear a genuine challenge in figuring and not just cheap tricks as suggested above
), for builders, bashers and miners I can remember some using (almost) only that one skill.
ISteve07: Bash and no Time - As the name implies, this one works exclusively with bashers.
ClamSpam04: Builders' Cracks - Builder puzzle, has one floater though.
Insane Steve' Cheapo Sets: Stairway to Somewhere - Another nice builder puzzle, makes use of a blocker and a floater though.
My Cheapo pack: Little Miner Puzzle - also makes use of one floater.
The latter three are coming close though, and it's most likely possible to make equally interesting levels without that one or two additional skills. Of course, when it comes to only using diggers, I'm am A.T. immediately springs to mind, which can be adapted to only use diggers. For miners (and possibly bashers), A.T. variants would also be possible, along the lines of I am I.S. (Part 2).