I've gone through a number of changes in my behaviour on the site since I joined more than 5 years ago. The reputation bug is a big driver for any newcomer to the site. However, while receiving reputation is awesome, giving it (through voting) should be reciprocated. If a post adds value, cast your vote. If that addition is negative or useless, downvote; if it's positive, upvote. If you're indifferent, then perhaps abstain. This is a fairly simple understanding of how the community grows. And it's really easy to get with the program.
For those of you who don't vote, challenge yourself. Try to vote at least once a day. I find myself often looking at user's profiles to see their voting activity. High-rep users with low voting behaviour is really a behaviour I don't fully understand.
While I know the community votes a lot, it is definitely telling to see that there had only been a "handful" of sportsmanship badgessportsmanship badges awarded thus far. In fact, there had been more altruist badgesaltruist badges awarded (first bounty on someone else's question). One way of interpreting this could be that people are really not willing to vote on competing answers because they may not end up on top, or, are only willing to vote if they've been voted for. Well then, if it's all about reputation for you, then know that without others voting, you won't be receiving much reputation yourself... reciprocate.