Are you rolling up characters you really care about playing or just whetever seems cool at the moment?
Without some form of personal investment in the character you probably won't stick with it.
I would reccomend that you take some time out of game to ponder what it is you enjoy doing. Whatever role you want to play - tank, healer, DPS - will help you narrow down your choices. Next, think about what aspect of that basic job floats your boat. If you want to provide DPS, do you prefer a fire wielding mage blasting things out of existance or a stealthy ranger decimating mobs with your bow from a distance. If you picked healer, do you prefer the heal over time skills of the druids or the reactive healing lines of the clerics. Or maybe you see yourself as award wielding shaman... All these characters do their jobs in unique ways and picking a style you enjoy will help you stay with the character.
And finally, think about what you would find visually pleasing or even stimulating. Do you fancy a gruff voiced dwarf or a gentle wood elf. Do you like the obvious, like wood elf rangers and dwarven fighters or do you like to play against type with an Euradite Pally or a wood elf necromancer...
Once you have a clear idea of the details of a character you would really enjoy playing, you'll find it much easier to sail past 20 and head for 50! Good luck and good hunting!
(edited because when I type fast... I get sloppy!)
Edited, Sat Feb 11 16:29:07 2006 by OldBlueDragon