A post today by Recursion King tackles the issue of dump stats. We've all seen it happen. A player will throw heaps of points into STR or DEX while stiffing CHA with as few as possible. The best solution to this is something I picked up from Greg Porter's rpgs. It's simple, straightforward and eliminates the problem at the point of character generation. The answer is to rule that a character's highest stat can't be more than twice their lowest stat. Trying to get by with a CHA of 5? That means your STR can't be more than 10. Want a CON of 16? Then forget about sticking only 6 points in INT.
The obvious exception to this rule is if lopsided stats are part of the character's persona and the player in question can be counted on to role-play the character faithfully. But players like that aren't the problem. This rule is intended to deal with your typical min-maxing munchkin. It works for me and I hope if you're having a problem with dump stats in your game it'll work for you too.
Or you could just play a random stat roll game like Call of Cthulhu...if you dare!