Good God some of you people are silly. The big reason to vote is this. If you give up your right to vote, you give up your right to bitch.
I don't understand this obsession with the Presidential race. When you go vote you do get to vote on other things also. I'll be voting for a Senator (a third of you will be doing the same), a Representative (everyone has this on the ballot), a state wide seat, and for County Commissioner. There are also state wide, school district, and local questions to be answered with a simple yes or no. I forgot to mention the judges on the ballot.
There are a lot of reasons to vote besides having a wee voice in who gets to live at 1600 Pennsylvania Avenue.