I don't grow tomatoes outside of the hoophouse in my zone five garden. There just aren't enough warm nights to get tomatoes ripe before fall cold and frost sets in. Putting them in the hoophouse gives me a much better tomato harvest.
To further increase warmth, I surround new plants with water (the wall-o-water effect.)
I am growing four varieties. Just a few years ago, when I was growing to sell at farmer's markets, I would start over 100 plants. This year I am down to 10 plants.
These are my varieties:
Sun Sugar, these are orange cherry tomatoes that are out of this world good.
Glacier, good tomato flavor in a 2-inch fruit, but these are super early, so I can start eating my own tomatoes fast.
Pruden’s Purple, a full size heirloom tomato, full of flavor, and very early maturing.
Black Plum - These are a the name suggests, black and the size of a very small plum. They taste good and produce very heavily. The other advantage with these is that they last forever. I brought the green ones in the house to ripen last fall, and had them until March.
Here are recommendations for tomato growing, from my website:
For more variety recommendations and growing advice, check out this forum at Gardenweb (if you can deal with the plethora of popup ads.)
Or a site I like is Tomatoville.
I hope you have a great tomato crop this year.