What is a man? A lot better than a vampire, given that it doesn't have to deal with +8 LA. Time to fix that.
All humanoids and monstrous humanoids can become vampires, which opens up some amusing possibilities (vampire tibbit, vampire gargoyle, vampire centaur). Obviously, their type changes to undead, which is generally a good thing. To compensate for the lost constitution, all hit dice become d12s (including future ones: wizards take notice!). Also, natural armor increases quite a bit, and ability scores are all boosted to varying amounts (with the obvious exception of constitution).
Of course, nobody plays vampire for the type or HD, they play it for the special abilities! Blood Drain is a lackluster start (something that's at most large won't be a good grappler), and Children of the Night is effectively a delayed summon that'll only be useful at low levels, but Dominate is pretty neat and Energy Drain is every natural attacker's wet dream. Kobold vampire rogue, anyone?
Alternate form is mostly useful for the at-will flight it provides, especially if your party members are light enough to carry along. Gaseous Form is kind of meh, but at least it's a nice exploration tool. Fast healing and DR are both very nice, as are the energy and turn resistances. Finally, there's Spider Climb, which is just confusing given the many other vampire abilities that do the same thing better.
Finally, vampires get five specific bonus feats (mostly bad ones, but useful for prerequisites), and a +8 racial bonus on half a dozen skills, which are overall quite neat.
Vampire weaknesses are annoying, but not to the degree that they impact the LA. Don't go out without sunlight-protection spells, and don't break and enter and you should be fine.
Given the sheer versatility of a vampire's abilities, as well as the general chassis upgrades, I feel like a LA of +3* (which would still let casters get 9th-level spells) is fine. The asterisk is here to account for spawn creation, which is of course too broken to allow on any kind of PC. Do discuss.