Just saw Darrell Hammond at San Jose's Improv. He was good, but not great. Most of his stuff is recycled, but it's mainly impersonations, so his routine never gets old. Hammond's Arnold Schwarzenegger impression is probably one of his best, and I also enjoyed his Bill Clinton and Jesse Jackson impersonations. Hammond thanked Bill Clinton for his house during the routine, and he doesn't seem to think too highly of the South (where he's from), Panda Express, or Hillary Clinton.
Jim Breuer, also an SNL alumnus, is still the best stand-up comic I've ever seen live.