I had my say about the All Star Game last year, so I'll link back to that if you want the argument.
Instead, I'll talk about what I usually do when I vote at the ballpark (which, alas, I haven't done for a few years...I've voted from home sometimes, but I never find it as fun).
What I do is a whole bunch of ballots. One is my favorite players. One is Giants in the NL and my Blue Sox heroes in the AL (yes, those two ballots tend to overlap a lot). One is something close to what I think of as the closest to what the game should be if it has to be something (which I don't really think): basically, who I think is the best player at every position right now. One is the best career-so-far. One is the guys who I believe have the best careers remaining (that's a fun one. Who has more remaining -- an all-time great 30 year old, or a 23 year old with great potential?). One is the guys who I believe will wind up with the best overall careers, eventually - that's a lot of fun, too. Depending on how much time I have, and how many chances I have, I can generate a few more, too. I suppose I might eventually get to "best year so far," but it's not one of my favorites at all. I mean, it's probably a better definition of All Star than my favorites or the All-Giants ballot, but it's not who I want to see in the game.
Oh, and one of the reasons I like doing it at the ballpark is that I don't like checking with anything. No looking up the stats. Now, I can't defend that as The Best Way to Do Things, but it's fun for me.