I've been using HP5+ almost exclusively for a little while now and have been very happy, in 35mm, 6x6/7 and 4x5. I was previously using a lot of the Delta films. It has very nice contrast and is forgiving of exposure. It can be comfortably pushed to 800 or 1600. It has more of a bite than Delta 400. If you like smoother, more buttery tones and grain, Delta may be a better choice.
Keep in mind that developer will have a large impact on your final product. I've had my best results with HC-110 developer, although I had to play with the times and dilutions for a while to get a good result. ID-11 and D-76 are sure bets, as well as the other ones mentioned in this thread.