Stars has the most players and is very good for tournaments, especially multitable sit and go's as they fill up quick and are very soft with most of the players playing the opposite of how they should (they play ultra loose and don't fold anything to begin with and then tight when the blinds are high and they should be getting aggressive). Full of Germans who are all horrendous especially heads up. Cash is not as soft, bit mixed. They do have some 6 max tables now but no real rakeback. Very good for multitabling. I've won the most money there. The customer service and security is generally considered the best around.
This is my stars sit n' go graph (actually mainly 45 man and 180 man tournaments, I have barely played any 9 mans).
http://img.photobucket.com/albums/v367/2hats/psgraph.jpgOn a slight downswing at the moment but I'm sure I'll recover.
Party is not as soft as it was. Software would be ok but it's always crashing for me, bonuses are pretty good.
Ladbrokes is good for cash, few too many scandies but standard is probably about average. Had a very good sign-up bonus.
Pacific is very soft but has terrible software. Very little 6 max last time I played there.
Pokerroom has some good tournaments, not played much cash there though. Standard is average.
Sky poker is the softest site due to the tv exposure which is good as I love playing bad players but the software is awful, no proper hand histories and very slow if you play more than 2 tables.
UB has very quick tables but didn’t have real hand histories last time I played there. Pretty good for cash and good rakeback and bonuses.
Wpex has the best rakeback but toughest players, far less fish and more regulars.
Overall I like stars best but I should probably find another site for playing cash