I have the United Signature Visa from First USA. I keep having such good experiences with them (in fact, so good that I dumped my Amex Platinum), while the general opinion of them on FT sounds quite low.

So I'd like to share the experience I had just a minute ago:

I had ordered quantity 2 of an item from an online merchant, was charged for quantity 2, received quantity 1. Merchant does not answer queries. Called First USA to dispute $53 of the $106 charge. Was issued a $53 credit instantly over the phone, after a conversation of about twenty seconds. Very nice. This is the best Visa card I've ever had.