Like a couple of others, I do max HP at every level. I started doing that in the waning days of 3e, when players became fewer and farther between and my groups got smaller. I discovered I really prefer small groups (like 3 PCs max), and the extra hp helps both keep them going and keep them trying new and daring stuff.
I also do max values for being potions and healing magic. The only thing that sucks as bad as rolling poorly for hit points is rolling poorly to restore them.
I should note that I run very sword-and-sorcery style games, so the encounters tend to be tough to brutal in difficulty, I don't have any magic items (including healing potions) for sale, and I often ban full casters aside from the warlock, so a PC's life isn't as comfy as you might suspect. I enjoy playing tough, and I like my players' characters to live long enough to enjoy it too.