Week 8 is in the books. The Broncos were dominant once again with an impressive blowout win over the Chargers, and right now Denver looks like a runaway train in the AFC. Denver's offensive attack is as effective as ever. Peyton Manning has integrated Emmanuel Sanders into his already loaded arsenal of weapons. At this point, it's possible that Sanders, who caught three touchdown passes on Thursday night, was the best free agent acquisition in the NFL this past offseason, at least on the offensive side of the ball -- and that's paying dividends for Denver.

Of course, the Broncos' defense is no slouch either, and it's proving to be one of the toughest groups in the NFL this year. Denver is strikingly balanced in all three phases. It's widening the gap from every other team on our power rankings.

Leaders of the pack

The Cardinals, who used their third fourth-quarter comeback this season to knock off the Eagles at home, move to 6-1 and appear to be the class of the NFC as we near the season's halfway point. Arizona has been remarkably successful this season despite key personnel losses, and possesses one of the top defenses in the league. Defensive coordinator Todd Bowles has his guys flying around, blitzing like crazy. The Cardinals have to be one of the toughest teams to game plan for because of their aggressive style. On offense, rookie John Brown continues to be an explosive playmaker for Arizona. He caught a perfect 75-yard bomb from Carson Palmer late in the game to take the lead back from Philly for good. With a seemingly healthy Palmer throwing passes to the rejuvenated Larry Fitzgerald and the always dangerous Michael Floyd, and handing off to the explosive Andre Ellington, this is an underrated offense as well.

Meanwhile, the Patriots put up a fifty-burger on the Bears, and appear to have regained whatever mojo they were missing on offense early in the year. It may be no coincidence, of course, that Rob Gronkowski is back healthy and integrated into the passing game. He caught three touchdowns in Week 8. Tom Brady went a cool 30-of-35 passing for 354 yards and five touchdowns. New England has now won four in a row.

Sitting in the No. 4 spot this week are the Detroit Lions, who came back from a 21-point deficit in London to knock off the Falcons and run to 6-2. The Lions are stronger on defense than pretty much anyone had predicted (and are one of the top defenses in the NFL right now). With Calvin Johnson out, offseason free agent acquisition Golden Tate is becoming a star. The Lions are getting it done with balance on both sides of the ball so their success seems sustainable, particularly when they get some reinforcements on the offense.

Parity rules

There are 18 teams in the NFL right now that have winning records. While the league's cellar dwellers continue to sink into rebuild mode, there's a robust group of teams that could challenge for the playoffs down the stretch.

The Cowboys lost to division rival Washington on Monday Night Football, taking a little wind out of their sails following a torrid first seven weeks. With the loss, Dallas drops to No. 5 in our rankings and while it'll have to deal with some injuries on defense, its offense remains a potent threat week in and week out. Luckily for the Cowboys, the Eagles lost a tough one as well. Although they're still trailing Dallas by a half-game, they obviously remain a contender in the NFC East. Their run game behind Shady McCoy is heating up, and that could pay dividends down the line. Not to be overlooked, Washington was the only team in the division to grab a win this week, and has now won two in a row after a slow start to the year. Can it be a threat as well? There's still time.

In the NFC North, the Packers lost to the Saints on Sunday Night Football, falling a game behind the Lions with the help of a gimpy Aaron Rodgers, hampered by a hamstring injury.

The NFC West and AFC North remain wide open. The Seahawks got a much-needed win in Carolina to pull even with the Niners at 4-3, and while both teams trail the Cardinals through eight weeks, the division-heavy part of the schedule is about to kick in for all three teams. The Bengals bounced back from last week's shutout at the hands of the Colts with a big victory over the division rival Ravens. The Browns and Steelers both got convincing wins as well, bringing all four teams above .500.

In the AFC West, the Chiefs won again, and combined with the Chargers' loss to the Broncos, things are starting to get more intriguing in that division. In the AFC East, the Bills and Dolphins are both quietly nipping at New England's heels and have each won two in a row. The Colts' loss and the Texans' win -- with the help of Arian Foster's fourth straight 100+ rushing game -- positions those two for a battle for supremacy in the AFC South.

Misery loves company

Nine of the bottom 10 teams in our rankings lost this week, so there's really not a whole lot to report. The Raiders remain the only winless team in the NFL after losing to the Browns, the Jags lost at home to the Dolphins and the Zach Mettenberger-led Titans lost to the Texans. The Rams, after knocking off the Seahawks at home last week, fell back to earth and were blown out by the Chiefs. The Jets lost and benched starting quarterback Geno Smith a week after trading for Percy Harvin.

Here are your rankings for Week 8: