A topic that's been beaten to death, with numerous opinions, styles, and house rules.
Yet, I really have to question how much it matters? Whether the wizard has 1 hp or 4 hp, a goblin with a bow or short sword will likely kill him with a single blow. I tend to be inclined toward making characters roll, but allowing either a reroll (take what you get, even if it's lower) or taking half the maximum.
While it doesn't seem to make much difference at 1st level, it can make a big difference at second level. A wizard getting a pair of 4s vs one that got a 2 and a 3 can actually survive a hit from that same goblin, even if it rolls high!
Of course using the rule that hit points are rerolled every level (without a base) then that isn't a consideration...
So I'm curious what my readers do. I have a poll up on the right.