During the summer, teams weren't shy about spending big bucks on free agents. A little more than a quarter of the way through the season, some clubs have been very happy with their investments, while others might be shaking their heads. During my next two entries, I'll take a quick look at some of the free agents who've made an immediate impact and some of those who have not. Let's start with the good news. Here are four guys that have been earning those new paychecks.