The Bard: Always has a great story that makes drinking sound even more awesome than it already is. There is romance! Adventure! Humor! Drama! Most likely a card accident or two! You always show up in one of these stories and you tend to be awesome. This guy is the Jeff Chaucer in your Knight's Tale and everyone now knows you are truly a hero.
The Mixer: This person doesn't own a copy of the Old Mr. Boston, he or she practically is Old Mr./Mrs. Boston. You can throw out any old beverage, and not only can he make if the ingredients are there, if they're not he knows the substitutes by heart as well. Rusty nail? Gotcha! Harvey Wall Banger? Coming right up! Rocket Fuel? I need to use your refrigerator coils if you haven't got any dry ice! Sometimes they'll come armed with their own shaker, and usually bring their own bottle of something nice for later on that night.
The Pop-Culture Hero: The flip side to the Pop-Culture Half-Ass, this person knows all the best lines from all the best movies, and often has other people help them out, adding to the party atmosphere. Part member of Whose Line Is It Anyway, part Alex Trebek, this guy or girl can quote anything and remember everything no matter how much they've had and still preserve the original punch of whatever they're quoting.
The Hidden Talent: This person does something really, really, really well. They lack enough self-confidence to do it in front of people, though. They practice it endlessly, meticulously perfecting whatever is they do, and they never tell you about it. One day, at a party, they get a few beers in them, and it turns out they can juggle. Grapefruits, in fact. That are on fire. They do a fine job and not only is it a great surprise, it is genuinely entertaining.
The Bon Viviant They're glad to see you, and you're glad to see them. It's been too long since we last tipped a glass! They know everyone there and they're sure to introduce you at some point. Never rude or crass, impeccably dressed, witty and endlessly conversational. Never utters "fighting words" or anything of that nature, and can generally round up the other four drunks you meet in Heaven for a kick ass little shin-dig.
The Wildcard:They guy nobody really knows, but dude is completely awesome. Fits right in with everyone at the party, is well spoken and cordial even if this is everyone's first time meeting them, and every so often, can play the piano really well, breathing life into that old thing for the first time since granddad died.