Ability scores, page 169 of the DMG and onward.
The Point Buy System: I think this is great for tournament characters and characters in multi-game and multi-party scenarios (because it equalizes all the characters), but I prefer other methods for home games.
The Elite Array: As above.
The Floating Reroll: It's a good system. It is more generous than the simple 4d6 system. If this method is taken, then PCs are better than ordinary people.
Organic Character: LOL. Take it, and like it. Or live with it!

Customized Average Characters: If you assume (as I once did in a hypothetical scenario) tha a 13 represents the top 1% of the population, and a 7 represents the bottom 1% of the population, then this system becomes more pronounced.
Random Average Characters: When I first started D&D, this is the method I had to use. And no rerolling characters. It sometimes stank. But I rolled Edena the Cleric up this way, and got: Str 13, Con 10, Dex 6, Int 14, Wis 17, Cha 16. Not bad, eh?
High powered characters: Just that. But it seems to me that in 3rd Edition, the effects of this system will be more profound than in 2nd Edition. Of course, if you allow your players to use this system, they probably will be very happy with you. (chuckles)
Many, many games I've been in used this system.
RPGA: The RPGA has to use the Point Buy system, in order to maintain character equality and fairness. Whether it's 25 or 32 points, it has to be used. Simple as that.
Subraces: You wouldn't believe how many dwarven subraces there are, on Krynn. I mean, we all know of the various elven subraces - so many, you have elven subraces coming out of your ears.

High, grey, wood, wild, gold, silver, green, valley, etc.
But did you know that there are dwarven Hylar, Daewar, Theiwar, Duergar, Klar, Neidar, Aghar, Zhakar, and Smith? And, of course, there are the Grey Dwarves, which are evil deep dwarves. And halflings come in varieties too: tallfellow, stout, deep, and cannabalistic (Athas.) And we have rock gnomes. That's a new one on me. They look like fey, I think.
Half-humans? LOL. Ok, I'd consider them variant half-elves. If Arilyn Moonflower had been allowed to live on Evermeet, she would have been half-human and not half-elf (and she would not hate Amlaruil's guts ... and I would daresay she is justified in hating Amlaruil's guts ...)
New Races:
Play a drow, you're 2nd level. Become a 1st level fighter, and you're 3rd level. And you must gain 4,000 experience points to make 2nd level as a fighter. That's what you get, when you take races with all those neat, special abilities at the start. Seems fair to me.
Play a vampire? LOL. Start at 8th level, first class makes you 9th. Nevermind that every cleric in the kingdom wants a stake put through you.
Now, what would be humorous, is if you had a party with both a paladin and a vampire (a good aligned one) in it.
A mind flayer as a PC?
Who will be on first watch?
Mind Flayer: I'll take first watch!
Everyone else: NO.
(If it's Anabstercorian who is the mind flayer, you're in worse trouble yet ...

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Ability Score Equivalencies:
So charisma is NOT the equal of the other stats. AHA! Told you so. And this gets reflected in where stats are placed.
I like characters with high charisma, even if it means lowering another stat.
Intelligence is equal only to Wisdom OR Charisma? LOLOL. Give me Intelligence. It adds to your base skill points, and in any case if you are a good roleplayer, it makes a tremendous difference. (That's right: if your character has a 6 intelligence, you shouldn't be roleplaying your character as a genius IMHO ... then again, stupid characters can be a lot of fun if played right ...)