I'll give this a whirl, why not, it's the off-season. These are my favorites, not necessarily the best players, though sometimes it's both.
Jun (BB4): Pioneered the floater strategy, hilarious diary rooms, and if you have the patience to put up with her prolific tweeting, she's one of the most entertaining BB house guests on Twitter. She's a one-woman soap opera.
Eric (BB8): Far more interesting than the edit he got, America's Player was a huge curveball in his lifelong dream to be on Big Brother, but he played it amazingly well. Also very funny, engaging, and interesting to listen to on the live feeds. He and Jessica were a fun pair to watch late at night.
Chelsia (BB9): Not a great season, but I enjoyed her on the show. I like her even more for the work she's doing now with Super Pass/Reality Nation - it can't be easy to deal with so many fans and house guests, but she's constantly trying to come up with engaging content, and has succeeded in making both sites more interesting for the fans.
Dan (BB10): Started off as the likable underdog and played his way to a well-earned landslide victory. Some of the most creative and surprising strategic moves ever seen in a BB winner. (What's up with this $40 how-to book he released today, though - jeez, c'mon, Dan?)
Hayden (BB12): I know, he was terrible TV. But Hayden played one of the most pitch-perfect games of Big Brother ever. He was a savant at the social game and survived many tight spots that would have sunk other players. Watching this guy on the feeds was a slow boil, but fascinating nevertheless.
Matt (BB12): Hated the wife lie (love the wife, they should have tried to get Stacy on the show more.) But despite some blind spots in his social game, his basic strategy was smart, and he was hilarious on the feeds.
Ragan (BB12): Loved him with Matt, I was invested in their bromance and the way they played off each other. Also liked that he was considerably smarter than the average Big Brother contestant. He made some game blunders on his season, but has a lot of interesting thoughts on the game and strategy overall.
Britney (BB12): Hated her til Monet left, but loved her after. Best Diary Rooms ever. Would be interesting to see her back in a future season and see her try to play smarter - she's a very bright and perceptive girl, she was just young and naive on her season.
Dominic (BB13): Left way too early. If he'd been on BB11 instead of Jeff, he might have been America's Sweetheart instead. We didn't get to see enough of him, but from what we saw on the feeds, he was charming, sensitive, and spunky. All the makings of a reality TV heartthrob, and he's probably still talked about more than any week three boot in the history of the show.
Daniele (BB13): Notice I put her down here and not on Season 8. In 8 she was a great strategist, but I found her whiny and had no interest in watching her build a relationship with Dick, when she clearly wasn't that interested in doing so (and for good reason). Liked her much more on her own in season 13, fighting to prove herself, and playing the underdog for several weeks in a row. Ultimately she couldn't dig herself out of a hole she put herself into, but watching her try was quite the ride.
So basically, I like funny, intelligent underdogs who use smart strategy.