Which size is best is more a matter of personal tastes than anything. My favorites are the 90 player knockout games at Full Tilt, the 180s at Pokerstars and the 5-table games just about anywhere online. 180 Player Sit N Goes are more similar to a multi-table tournament in structure and make a great training system for those players who are looking to make the transition to the larger poker tournament scene. Read more...
Winning multi-table games, whether 2 or 20 tables, is all about your ability to adjust to the changing situations. You will be playing with full tables at higher blinds than in the single table version of the game, and will also need to adapt to bigger differences in stack sizes than in smaller games. We have a large number of strategy articles on different sized Sit N Go tournaments here at SNG Planet. If there is anything we do not yet have then you are welcome to let us know at support@sngplanet.com, we will do our best to have someone on the case as soon as possible!