My partner's favourite t-shirts were Bella... until she got an Alternative Apparel tee. Bella still ranks a respectable second, but she (for one) prefers Alternative. Either company would be a huge boon over other brands though.
As a side note the Bella rib is a lot nicer than the standard weave (but then that may well be true of any company... one for me to experiment with I guess).
Size wise... Bella rib stretches nicely and is roomy, but their non-rib stuff runs a bit smaller than Alternative.