My vote for Best Mainstream & Large Scale Social Network is easy: Twitter.
Of the other nominated sites, I also use: Facebook, FriendFeed, MySpace (I have to, they make me), and Squidoo, but Twitter is the only one I use everyday, continuously akin to a junkie with heroine. I cannot stop! I have tried, but I just can't.
I have tried the alternatives:
Plurk was too gimmicky.
Jaiku was too complex and no fun.
Pownce made me fear the wrath of the RIAA (Mike makes a good argument for it though)
Indenti.ca didn't have the community I wanted.
Whenever there is an event, I just load up Twitter (like I turn it off) and join in the conversation. It is fun, and easy. The 140 character limit keeps it readable. As my number of followers grow and the number I follow, the brevity becomes an asset.
The apps make Twitter work.
- Twirl for posting and reading.
- TweetDeck for tracking opinion.
- Twellow for finding people.
- Twitterific for mobile tweeting.