One of the best things about the NFL is the parity. Unlike any other sport, every team has at least a chance at competing from week to week. This leads to exciting upsets and, more importantly, quick turnarounds. Teams can go from worst to first, or at least worst to half-way decent, in just one season. That gives fans hope and every year an added layer of excitement.

Let's take a look at the top three turnarounds this season.

1. Dallas Cowboys

The Cowboys had slogged through three consecutive .500 seasons before this year. In that time, Dallas was the epitome of mediocrity. Coming into this season with MAJOR question marks on defense had many thinking that the Cowboys could be in line for a top five pick. Instead, unlikely contributions from Rolando McClain and Barry Church has this team playing solid defense. A revamped offensive line that features three former first-round picks has DeMarco Murray looking like a legit MVP candidate. Dallas' win over the Seattle Seahawks on Sunday is easily the most important victory of the NFL season so far. At 5-1, the Cowboys are well on their way to breaking their recent string of 8-8 seasons.

2. Baltimore Ravens

The Ravens also finished last season at a disappointing 8-8. Joe Flacco didn't retain that post-season magic that delivered a Super Bowl trophy to Baltimore. The defense had holes in it and the offense was inconsistent. The Ravens, at 4-2 with losses to two of the best teams in football (Cincinnati and Indianapolis), look vastly improved from last season's dull squad. Steve Smith is playing out of his mind with 35 catches for 573 yards and four touchdowns and Justin Forsett has been an unexpected catalyst in the running game. Plus, Baltimore is only allowing 90 yards on the ground to opposing rushing attacks. If the Ravens can keep this up than they'll no doubt be a force in the AFC North.

3. Houston Texans

The Texans finished an NFL worst 2-14 last season. While everyone knew they were more talented than their record suggested, it's still nice to see them eclipse there win mark already at 3-3 this season. J.J. Watt has been his typical self, meaning absolutely ferocious. Second-year receiver DeAndre Hopkins has looked like a star in the making at times. Sure, this team could shore up its secondary and use a consistently healthy Arian Foster. Yes, first overall pick Jadeveon Clowney has been out since Week 1 with a knee injury. But the main thing holding this team back is quarterback Ryan Fitzpatrick. Look for Houston to upgrade its quarterback position in the offseason. After that, this team could be dangerous.