3/4 cup is a good healthy amount of corn sugar, but it's not going to turn your bottles into all foam or anything. Remember that at some point the carbonating is going to stop because there will be no sugar left to feed the yeasties.
There's a good carbonation calculator at the beer recipator page (too lazy to look up th URL: google beer recipator), which tells you what the range of carbonation for your style is, then calculates how much priming sugar based on the amount of beer, what the priming sugar is, and what level of carbonation you're going for.