I'm a fan of 1728 and 1028 for both porters and stouts. Sure, the Chico strain is fine for them, too, but the other two make for a more interesting dark beer, I find.
There's something funny about the 1728, too. At first, it's good, but nothing special. Age that porter/stout for a year, and it seems to develop some wonderful dark stone fruit flavors. I've had that happen with several beers now. It's subtle, but very interesting and satisfying.