My husband and I eloped when we were students and paid for everything ourselves, so my wedding ring (never got engaged) is a cheapo job, just a plain gold band. But what does it matter? We're married almost 12 years, I don't think we'd have been happier if he'd given me a big diamond ring.
We've been talking about upgrading our rings though, just for fun. I think I'd want the same type of ring, plain gold band, but thicker than what I have now.