I like my Craftsman 19.2V stuff. I have the NiCd batteries, which work fine for what I use them for (general homeowner stuff). You can also get them for pretty good deals, although I've heard really bad reviews on the innerwebs about the batteries not making it past a year. For general homeowner stuff, they're pretty good, though.
Probably the best reviewed units I've heard of are Bosch or Makita.