Vertbaudet jeans are suprisingly nice - don't look that good on the website, but I just got given some handmedown ones from last year, and I love them, and would definitely buy more in future pregnancies.
As for non-maternity stretchy clothes, might be worth browsing Uniqlo and American Apparel sites for tops, leggings and stretchy dresses and skirts, I'm 7 months and a lot of stuff fits in the larger sizes. I also thought it might be doomed to failure and I would be arrested for impersonating (badly) a 20 year old, but there's a lot of good stuff there, and you don't have to dress top to toe in it. I've also found Uniqlo stuff perfect for sleeping in since my normal pyjamas/whatever no longer fit, and my normal t-shirts no longer cover my tummy.
Someone mentioned on MN a while back that Uniqlo are doing bra-tank tops at the moment - tank tops with rather unattractive bra insert in them. Excellent for sleeping in if you're feeling a bit bigger or sorer than usual.
Finally, I found a really nice (but expensive) non-maternity brand, Dutch company called Humanoid, that do dresses and tops that you can get away with buying normal size for, your tummy will fit, and it will still fit/look good when you're no longer pregnant. It looks like you can't order direct from website, but worth looking at in shops in your city (should be listed at www.humanoid.nl). In London, they're stocked by Folk in Lamb's Conduit Street - looks like a silly boutique (and is expensive) but amazingly the staff are human and extremely kind and friendly. I needed something for a wedding, and it just looked better on me than the wrap dresses that all the maternity wear companies seem to specialise in - nothing wrong with wrap dresses, it's me that looks horrible in them.