For the Viper, I've only used the stock battery. It fits, at least, and goes bad after about four or five years, but I can live with that.
I'll second a recommendation against AC Delco batteries - I got an average of 14 months with them - worst ones I've had the displeasure of using.
I'll also second Sears Gold DieHard. Other DieHards aren't worth the name, but you do actually get closer to your money's worth with the more expensive Sears Gold DieHard - at least I did with the one I had in another car. I lost the alternator belt and ran a total-loss system for a full week of 20 mile round-trip commutes (with headlights, heater blower, windshield wipers, and stereo) on my '88 RX-7 convertable before I noticed things were getting dimmer, then popped the hood and found pieces of my belt all over the place.
I've had good luck with Interstate batteries, also.