UFC 100 betting odds varied across the board.  There were several big payouts to be had with any number of upsets.

Paulo Thiago would pay out around $400 for every $100 bet at Bookmaker.com should he upset Jon Fitch (-400 odds most establishments).  Some online gambling websites had Thiago paying under $300 for every $100 bet with a win.

Jake O'Brien would pay out $300 for every $100 bet at Sportsinteraction.com should he manage a win over Jon Jones.  This line was pretty consistent across the board.

Another big underdog with potential to pay out big was Mark Coleman ($300 for every $100 bet at Bookmaker.com).

Of the main cards, Thiago Alves was being offered up at +260 odds at SBG Global for a payout possibility of $260 on every $100 bet.

Frank Mir and Michael Bisping both had UFC 100 betting odds of +200 in their respective matchups. Sportsbook.com had Bisping paying $200 for every $100 bet and Mir paying $190 for every $100 bet. 

Other underdogs included:

Tom Lawlor priced at $250

Mac Danzig priced at $160
T.J. Grant priced at $190
Alan Belcher priced at $220

Tyrone Darnell Black, Gambling911.com