Cha. No matter what my main stat is, I’ll have good Cha. (14-16, unless I’m going for a particularly charismatic (not necessarily Cha-based) character, in which case 18+.)
Str/Con based? Big, burly, and VERY good at making you think they can and will break you - so they don’t have to bother actually doing so.
Int based? People listen to them talk, rather than writing them off as a nerd.
Wis based? Well, I only do Wis-based (as opposed to simple high-Wis) when playing a D&D Cleric, so why they’d want high-Cha is obvious.
Dex based? They’re lithe and pretty, as a consequence of being all dexterous. Also, usually very likeable goofballs.
Being Really Damned Pretty is also a valid alternate or addition to any of the other ones, as well. Or Really Kinda Odd-Looking. I tend to want characters who are interesting to look at, be they big and ugly, slender (or zaftig) and beautiful, or look like an Egyptian deity. So, high Cha, FTW.