Not getting too exotic, I've had pretty good luck with redwood.

 

I agree with Willie T.
I would probably just use pressure treated pine. Wait a few weeks for it to dry out a bit before I primed and painted.
Regards,
Joe

 

white cedar

Northern or Atlantic white cedar.

 

The 4x4 posts holding up my porch roof have been there since the house was built in the mid '70s. The wood comes in contact with the cement beneath it.

I just took off all of the boards surrounding these posts because they were rotted at the bottom. When I got all of that wood off, I found that the 4x4 posts look like brand new. There wasn't even a trace of water damage or rot after about 35 years.

It's pressure treated and says, "Ground Contact" on it.

FWIW

 

For a painted application, treated wood is less than desirable. The high moisture content and the Southern Yellow Pine species just don't make a stable product if you want it to look good long term. I'd lean towards redwood or cedar, and make sure it is reasonably dry before painting. Prime, then paint all surfaces.

 

Based on your location I would recommend cedar if you want to keep costs down.

 

I am using treated wood and then cladding it in white cedar. You can see some pics of my project here:
Blog link removed

 

Pine won't be bad if you waterseal it first, preprime all 6 sides, etc. Proper upkeep, caulk, paint, etc. will keep it nice for a long time.

You might want to look at pvc. It is terribly expensive, but you will NEVER have to paint it. The time, upkeep, and future paint, etc. will help balance the cost.

 

I like to work with douglas Fir, Its not a true fir , its denser than Pine or Fir. ( compare equal length pieces by Weight.)
or, since your in the east, check out recycled wood dealers , you may find some great Hardwoods you can mill and Love.