Tons of options... yeah that's a tough one. It depends on who you're trying to please, I'd say. If you're like me and create themes mostly for yourself, you can settle for only basic customizability (is that a word?) in case someone else likes your theme and wants to use it. On the other hand, if you want as many people as possible to be able to use your theme, you'll have to add a lot more options to cater for different preferences.

Personally I would never add options to change every single thing. I've always felt that if a user wants to change everything in a theme -- fonts, colors, layout, behavior -- I think s/he would be better off chosing some other theme that's closer to what s/he is looking for instead of asking the themer to modify his design to crap. That's just wasting everyone's time.

I think it's sort of amusing when people say "I really LOVE this theme, but please change this and that and make that thing go here and the colors are too dark/bright/whatever -- and oh, can you add [feature] too?" -- I mean WTF, what was it that you loved about it anyway? The file size? :D