It was a few years ago, but I remember geeking out on batteries when it was time to replace the one in the Civic. I really wanted an Optima (because cool new technology!), but in the end cheaped out and bought whatever from Crappy Tire. It was cheap, worked just fine, and lasted until I sold the car (5-6 years, IIRC).
It was the same when I needed a new deep-cycle battery for the travel trailer. Researched dual 6V options, looked at the Optimas again, then woke up one morning before a trip and realized I'd frozen the battery and the case had cracked. Oops.
Went to NAPA, and again bought whatever they happened to have. It's been fine for three years now.
Not sure what I'll do when the original one in the GTI dies. Might be a weird German size, but otherwise I'll probably just get whatever they have at CT and not worry much about it.