Mashable's Face-off Series

Mashable has been running polls for a couple of months now, pitting two (or three) apps/companies/technologies against each other and getting their readers to vote.

Here are some of the past weeks' results:

Week 1:
- Mozilla Firefox vs. Google Chrome
- WINNER: Firefox, 4600 votes (Chrome: 3310 votes, Tie: 911 votes)

Week 2:
- Tumblr vs. Posterous
- WINNER: Tumblr, 1809 votes (Posterous: 1496 votes, Tie: 256 votes)

Week 3:
- Pandora vs. Last.fm
- WINNER: Last.fm, 1187 votes (Pandora: 1156 votes, Tie: 122 votes)

Week 4:
- Twitter vs. Facebook
- WINNER: Facebook, 2484 votes (Twitter: 2061 votes, Tie: 588 votes)

Week 5:
- WordPress vs. Typepad
- WINNER: WordPress, 2714 votes (Typepad: 267 votes, Tie: 357 votes)

Week 6:
- Windows 7 vs. Snow Leopard
- WINNER: Windows 7, 3632 votes (Snow Leopard: 3278 votes, Tie: 121 votes)

Week 7:
- TweetDeck vs. Seesmic Desktop
- WINNER: TweetDeck, 3294 votes (Seesmic Desktop: 1055 votes, Tie: 260 votes)

Week 8:
- Microsoft Office vs. Google Docs
- WINNER: Microsoft Office, 1365 votes (Google Docs: 994 votes, Tie: 315 votes)

Week 9:
- Apple iPhone vs. Google Android
- WINNER: Google Android, 3323 votes (Apple iPhone: 1494 votes, Tie: 228 votes)

Week 10:
- AT&T vs. Verizon
- WINNER: Verizon, 1161 votes (AT&T: 538 votes, Tie: 118 votes)

Week 11:
- Google vs. Bing
- WINNER: Google, 2180 votes (Bing: 519 votes, Tie: 97 votes)

Week 12:
- iPod Touch/iPhone vs. Nintendo DS vs. Sony PSP
- WINNER: iPod Touch/iPhone, 704 votes (Sony PSP: 639 votes, Nintendo DS: 482 votes, Tie: 108 votes)

Week 13:
- Digg vs. Reddit vs. StumbleUpon
- WINNER: Digg, 14,762 votes (Reddit: 11,466 votes, StumbleUpon: 2507 votes, Tie: 1032 votes)

Week 14:
- Old versus new Twitter retweets
- WINNER: Old style retweets, 1625 votes (New style retweets: 699 votes, Tie: 227 votes)

Week 15:
- Gmail vs. Outlook
- WINNER: Gmail, 3684 votes (Outlook: 980 votes, Tie: 590 votes)

Week 16:
- Boxee vs. Hulu
- WINNER: Hulu, 626 votes (Boxee: 591 votes, Tie: 106 votes)

Week 17:
- Nexus One vs. iPhone 3GS
- WINNER: Nexus One, 6743 votes (iPhone 3GS: 2818 votes, Tie: 592 votes)

Week 18:
- Foursquare vs. Yelp vs. Gowalla
- WINNER: Foursquare, 1182 votes, (Yelp: 661 votes, Gowalla: 509 votes, Tie: 143 votes)

Week 19:
- AIM vs. GTalk vs. FbChat
- WINNER: GTalk, 2189 votes, (AIM: 1257 votes, FbChat: 511 votes, Tie: 203 votes)

Week 20:
- Music Ownership vs. Music Subscription
- WINNER: Ownership, 533 votes (Subscription: 299 votes, Tie: 237)

Week 21:
- Match.com vs. PlentyofFish
- WINNER: Plenty of Fish, 430 votes (Match.com: 334 votes, Tie: 187 votes)

Week 21:
- Google Buzz vs. Facebook Vs. Twitter

- WINNER: Facebook, 3353 votes (Twitter: 1828 votes, Google Buzz: 1298 votes, Tie: 651 votes)

This week's poll: Adobe Flash vs. HTML 5

Which will you vote for?