gilden ultra cotton are good (i have several in the closet that are 12 y/o, still in good shape), i also like anvil, and beefy-t..all in 6.1 oz. i think there all about the same, but i will try both anvil and gildan, and end up using one of those. beefy-ts are good, but you're paying for hanes healthy advertising budget.
i'd also stick with 100% cotton, unless your doing some form fitting designer shirts..then i'd just go shopping for what you want to print on, google the product's tag to find matching or similar products.
ps. if i bought a shirt on-line, as expensive as most tend to be, and it ended up being a 50/50..that would be the last shirt i bought from that site. not that i wouldn't sell them, but i'd reduce the price and inform the buyers the reason for the discount pricing. some people probably don't care, but i (like you), don't care for them.