On first playthroughs I usually use my name, because when I was little and I first played ALttP I didn't realize the main character was a guy (I thought Link was Zelda) so I gave him my name, even though i'm a girl and it's a girl's name. Ever since I just give him my name on first playthroughs out of habit/tradition. (Actually I used to give every video game character I could my name, regardless of gender, then I just decided to go with defaults, and now I try to make up a name.)
Anyway, on second, third, etc. playthroughs I name him Link if I don't feel like making up a name, or something different like Batman, or Agent007.