freerolls - no! This is actually the epitome of variance.
A high variance in poker means you are not winning what you should be because of many different factors.
My opinion of the top 5 factors, in order, of what makes the game high variance are:
5. You are a loose aggressive player
4. Your opponents are loose aggressive players
3. The limits of the game - NL vs. PL vs FL/SL
2. Game - Texas Holdem, Omaha Holdem, Stud
1. Game type - cash, SnG, MTT, Satelliets, Freerolls
loose aggressive play causes more variance because
hands that typically shouldnt win do win more often
No limit games have high variance because the bets can be exponentially larger than the blinds and antes, and the more money you can risk the higher the variance can be
Omaha Holdem has less variance than Texas Holdem because Omaha hands generally have less of an edge against each other when all in, variance is losing when you should be winning, and in Omaha there is no super advantage from one hand to the next, in Omaha the average of one hand winning against another is 60/40, whereas in Texas Holdem its more like 75/25, the higher the expectation that you should win and dont = higher variance
With this being said, the least variance game would be limit omaha or limit stud games, yes they are boring, but thats the thing - variance is exciting and addicting.
The more people that play the more variance because the likelihood of you winning is so low to begin with, plus the more styles of play you will encounter.
So this means that 6 seated cash games are better than 9, and smaller tournaments are better than bigger. Heads up obviously has the least variance of all in either cash or tourney.
SNGS are best, especially the dbl or nothings, for tourneys.
So lets look at the freeroll - way to many people, way to loose and aggressive play, usually no-limit Texas Holdem - most variance EVER