5 of a kind is the best but you need to be playing a poker game with wilds for example Baseball.
Also depending on what game you play there is whats called the Wheel which is a straight A-5 which is best or 2-3-4-5-7
Razz is a game where you try to get the worst possible hand in 7card stud.
With the wheel being the best.
Check
http://www.worldseriesofpoker.com/learn/rules.asp for some particular rules for certain games. Which are complicated to say the least at times.