For Pure tone ... get a tube amp!
Depends on your style, but you can't beat the standards from Fender or Marshall. It depends on how much cash you have as well. My main amp is a 60 watt Rivera head with 4x10 cabinet, but I also have a sweet customized Fender Blues Junior for the grab and go situations. Pluf my Strat or Tele in this amp, which was less than $500 and it sounds great.