Day 1 of free agency was a busy one. Here's a look at the top 10 signings (through 10:30 p.m. ET) in descending order of the impact each player will have on his new team:

1. Marian Hossa to Chicago
What was it the Chicago Blackhawks were missing against the Detroit Red Wings in the Western Conference finals when the playoff-savvy Wings dispatched the Hawks in five games? Was it a top-notch forward who is hard to knock off the puck and can play in all three zones? If it was, then the movement of hard-luck Hossa (a Stanley Cup runner-up with different teams the past two springs) down the Central Division highway might be the tipping point if the two teams happen to meet on the same stage in 2009-10. That's certainly how the talented, youthful Blackhawks hope it plays out.
• Impact-o-meter: 9.5 | Signing details | Free-agent tracker


2. Daniel and Henrik Sedin re-sign in Vancouver
Let us ask you this: Did any other team add 160 points a season in offense on the first day of free agency? That's what you get with the consistent and talented twins, and that's what, in the end, Canucks GM Mike Gillis knew he couldn't afford to lose. He had to pay more salary than he wanted, $6.1 million a year, but he got the Sedins in the five-year deals he wanted all along instead of the 12-year proposals offered by the players' camp. Some teams are head over heels to add one player of this caliber. That Vancouver was able to keep both star forwards in Canucks uniforms at the peak of their careers could very well be the biggest transaction in franchise history. Because believe us, Toronto, among other teams, was waiting for the clock to strike noon ET.
• Impact-o-meter: 9 | Signing details | Free-agent tracker

3. Marian Gaborik to New York Rangers
Two years ago, the Rangers thought they had struck Stanley Cup gold when they signed top free-agent centers Chris Drury and Scott Gomez. Last offseason, they thought they had turned a Stanley Cup corner with Markus Naslund, Nikolai Zherdev and Wade Redden. Is Gaborik the long-awaited answer? If the brittle Slovak winger stays healthy, he's a 50-goal man and one of the most dynamic offensive forces in the game.
GM Glen Sather, who has tendered some of the worst contracts offered in NHL history, deserves credit for being able to maneuver out of Gomez's contract (he was traded to Montreal) to free up the cap space and have the ability to make Gaborik an offer. Gaborik's deal is five years, worth an average of $7.5 million a year. Gaborik can be the kind of player the goal-starved Rangers dreamed about the past couple of years. If he is, New York is a Cup contender. If not, it will be yet another year of the Rangers pouring good money down the drain.
• Impact-o-meter: 8 | Signing details | Free-agent tracker

4. Mattias Ohlund to Tampa Bay
Take a close look at the Tampa Bay Lightning. Beneath the veneer of chaos and disorganization that has marked the team these many months lies the heart of a team that isn't far removed from being a playoff contender. Vincent Lecavalier is still there; so are Martin St. Louis and Ryan Malone. The blue line was racked by injuries and a constant merry-go-round of personnel last season. But, assuming decent health, the addition of top-end, dependable Ohlund, who signed a seven-year deal Wednesday, might be the catalyst to a return to the playoffs, and respectability, for the Bolts.
• Impact-o-meter: 7.5 | Signing details | Free-agent tracker

5. Mike Cammalleri to Montreal
His 82 points last season would have led the Habs (comfortably) in scoring, 17 points better than leading scorer Alexei Kovalev. Cammalleri's 39 goals were also 13 more than Kovalev's team-leading 26 and more than any Habs player in any post-lockout season. So, yes, Cammalleri's offensive addition is welcome in Montreal. No question he doesn't have Jarome Iginla to play with anymore, but we figure he'll be just fine with Gomez and Brian Gionta. He might not have the all-around game of Hossa, but we're betting he's going to score nearly as many points.
• Impact-o-meter: 7.5 | Signing details | Free-agent tracker

6. Mike Komisarek to Toronto
Let's be clear on one thing -- Komisarek isn't Jay Bouwmeester or Dion Phaneuf or Shea Weber or any of the hot blue-line studs who dot the NHL landscape. If folks in Toronto think that's what they're getting after GM Brian Burke landed his biggest fish since taking over the Leafs, there will be great disappointment in Leaf Nation. If the fans of the blue and white understand they've obtained a hard-nosed, hard-hitting, smart-thinking defenseman who can play shutdown defense against the opposing teams' best forwards, they'll be more than happy. Komisarek didn't have a terrific year in Montreal (name someone on that squad who did), but he has terrific upside and is a Burke player through and through. It's hard to overstate the importance of this kind of addition for a team that's been too easy to play against since the end of the lockout.
• Impact-o-meter: 6 | Signing details | Free-agent tracker

7. Nikolai Khabibulin to Edmonton
You have to praise the Oilers for reacting quickly to the loss of starting netminder Dwayne Roloson by replacing him with a Cup champion in Khabibulin. But let us also pass this along: The Hawks' front office privately believed Khabibulin wasn't quite up to snuff in the playoffs, as underlined by his .898 save percentage in 15 postseason games. Which Khabibulin will show up in Edmonton: the rock-solid regular-season goalie of last season or the playoff version? Still, no matter what happens, Oilers GM Steve Tambellini wasn't flooded with options on the market with Khabibulin and Martin Biron clearly the best two choices. Edmonton landed the goalie who has won a championship.
• Impact-o-meter: 5 | Signing details | Free-agent tracker

8. Brian Gionta to Montreal
Maybe a change in scenery -- and a reunion with an old linemate -- will help reverse the downward spiral in Gionta's offensive production. After tallying 48 goals in 2005-06, Gionta has recorded seasons of 25, 22 and 20 goals. Montreal GM Bob Gainey must think Gionta still has the tools to put up top-end numbers, though, as he signed the diminutive 30-year-old winger to a five-year deal worth an average of $5 million annually. One assumes new coach Jacques Martin will give Gionta a chance to play alongside old Devils linemate Gomez, and perhaps Cammalleri will get in on the action, too. Regardless, the addition of the three skilled players should make the Habs much more dynamic offensively than they were a year ago.
• Impact-o-meter: 5 | Signing details | Free-agent tracker

9. Mike Knuble to Washington
Sometimes, it's after the fact that you remember these kinds of deals, when a team wins a seventh game on the road or kills a penalty to preserve a much-needed victory or when a respected veteran speaks candidly to the media about what ails a team in a low period. Well, Knuble is the kind of guy who has the potential to contribute all these intangible elements that separate winners from losers and contenders from pretenders. Knuble can kill penalties and contribute on the power play, but he was really brought in to help the Caps separate themselves from the pack next spring. Hard to imagine he won't.
• Impact-o-meter: 4 | Signing details | Free-agent tracker

10. Steve Sullivan re-signs in Nashville
On a day in which the Predators lost Vernon Fiddler and Greg Zanon to free agency, they at least were able to keep their most important free agent. Sullivan is not only a major point producer for Nashville but is also an important team member off the ice. The small-but-loyal following of Predators fans absolutely love this guy. If his back stays healthy, we're predicting a 70- to 80-point season for the "Timmins Tornado," and that's the kind of offense the frugal Preds never would have been able to replace in free agency.
• Impact-o-meter: 4 | Signing details | Free-agent tracker
Scott Burnside and Pierre LeBrun cover the NHL for ESPN.com.