I have to agree with jmhewitts comments about the "Fourth Of July" variety. It was easily the earliest and most productive tomato in my garden this year. The plant itself was very robust producing suckers and side shoots rapidly as it grew. I had to keep removing excess growth to prevent the plant from taking over the bed. Every new growth quickly produced another truss loaded with flawless, golf ball sized fruit. The earliest fruit (55 days) were a little flat in taste. After a week of production, the taste improved so much I would rank them with any red tomato in my garden. The tomatoes on the trusses ripen individually. I wish they would produce and ripen at the same time on the truss, but it doesn't really matter.
Here is a photo of one of my Fourth Of July plants. This photo was taken early in the season and low on the plant. You can see some fruit near the bottom beginning to ripen. You can't see them, but higher on the same plant; the fruit was much more abundant but buried deep in the foliage.
A friend on another forum grew Fourth Of July for a few years with great results and then switched to a variety named "Sweet Cluster". He claims Sweet Cluster has all of the attributes of Fourth of July plus it is even more productive with better tasting tomatoes. I find it hard to believe, but I suppose I will have to try "Sweet Cluster" next year along with the Mountain Magic Carolyn mentioned. I wanted to try Mountain Magic this year but didn't get seed ordered in time to grow them.
Ted