I bought a 32GB iPad 1 for my husband, but only because I figured he'd barely use it. For him, it's just streaming video or podcasts while he cooks. I synched it with my iTunes account and found it really annoying to have to limit what I loaded.
I've nearly filled my iPad 1 and 2, both of which are 64GB 3G. With future purchases, I will consider only models with at least that much space.