OK, this is a recipe I have designed in my quest for a nice session porter with a big flavor. It started in the style of an English brown porter, but it differs from that style in that it is darker in color, has a bigger chocolate/coffee flavor and has a fuller mouthfeel. The mouthfeel comes from a fair amount of non-fermenting malt sugars and a yeast that is rather low in attenuation. I call this beer an American tribute to the English brown porter.
I stayed with an English hopping approach. I wanted to keep the alcohol below 5%, so based on your efficiency, you might want to modify the amount of pale malt a little to shoot for 4.5-5.0% alcohol. That way you can drink several pints of this delicious, chocolatey, full-bodied ale, and still be in decent shape.

For a 6-gallon batch (6 gallons in the fermentor):

Grains
69% 9 lb American Two-row Pale
12% 1.5 lb Caramel/Crystal Malt - 60L
12% 1.5 lb Munich Malt
6% 0.75 lb Chocolate Malt
2% 0.25 lb Roasted Barley

Hops
2.25 oz Goldings - 60 min. (4.5% AA)
0.5 oz Goldings - 5 min. (4.5% AA)

Yeast
London ESB (Wyeast 1968) - chosen for some fruitiness, somewhat low attenuation, and high flocculation. Substitute any similar English yeast.

OG 1.046 (my process has low efficiency of about 60%)
FG 1.012
Alcohol - 4.5%
IBUs - around 35
SRM - around 33