Yes, a VERY good question!!
I'm like you Karen - I like a T to have some viscose in it - I just find they wash and wear so much better. And agree on the SES quality... but hey, for $7 they are still fun LOL
I do like my portmans tops, but seeing as we have no clearance stores of any nature here at all (oh except a Rivers Clearance Store), the best I can get is their regular sales - and that still makes them a relatively expensive purchase.
I have a couple of things from Sussans and have been happy with their quality, but I've only ever bought wovens, so can't comment on their knit items - but again, I find them a bit exxy for me.
Big W I have a couple of knit tops from as well now I think about it! They are washing and wearing well, but the seams aren't dead straight anymore - do you know what I mean - when they kind of get a bit skewed to the front/back? Its not at all that noticeable, but just something I notice when I iron...
We do seem to lack a consistently good, fairly priced, basics store here though in my opinion!