I had an Optima batter in the beginning and at some point, I figured it was dead (don't remember the specifics, it was some time ago). Since then, I've gotten regular old lead/acid batteries. They are cheaper and although a good charger would be better, they seem to be able to take garden variety trickle chargers (I use an old 3 amp charger for mine). If it doesn't last as long, I figure I might have let it discharge to far and I get another. At about $100 or so, it doesn't hurt that much but when you get toward $300, that's not fun.
I have heard a lot of good things about Odyssey batteries and literarymadness told me he was using some fancy lithium ion battery and he likes it.