Orange Kentucky Beefsteak is actually yellow, and very tasty, tart and slightly sweet, plus they can get big, easily over one pound. We've tried maybe 40 varieties for three growing seasons, and this one will always be in our garden. Plant can get YUGE, so give it plenty of room. I space all my tomatoes at 4ft, and this one fills that space.
I second yellow Brandywine, very good flavor, but a shy bearer. Huge beautiful plant with potato leaves, but stingy producer.
Dr Wyche Yellow produced well for us last year, but flavor was a bit off, but a lot of our maters lacked in flavor last year. More on me and the humid rainy summer than the fruit, probably.