Hiya!
Wow, you guys are generous!
I've used, for decades now, my method where max HP at first level (unless we're playing Hackmaster 4th; then roll). Every level gained after that, roll...with the player having the option to let me roll for them if they don't like what they got. They keep my roll no matter what though...even if it's lower.
For example: A fighter rolls his d10 for gaining a level and gets a 4. The player opts to have me "re-roll" it; I roll a d10 and get a 7. He gets +7hp. Or maybe I re-roll and get a 1. He gets +1hp.
This has really cut down on both really high and really low hp totals...bringing it more in line with what the game is geared toward, IMHO. Exceptions come up (like a recently deceased 5th level Goliath barbarian who had something like 74hp!... or the poor 4th level thief who had...14hp or something like that?), but for the most part the HP's keep towards the middle without getting too crazy.
It also has the added benefit of curbing players desire for "super characters", believe it or not. I'm not sure of the psychology involved, but for whatever reason, since I started doing this 20+ years ago for all my "D&D'ish" games I've seen a decrease in player desire to try and 'fudge' their character rolls, be it HP, gold or whatever. *shrug* I'm not looking anywhere near that gift horses mouth!
^_^
Paul L. Ming