I voted Toyota Tacoma. The Nissan Frontier is also a fine truck, and something I'd consider. I haven't looked at the Chevy Colorado yet, but I'm on my third S10 and really like Chevy's small trucks. Mine is all paid for, though, and only has 60K on it, so I really can't justify truck shopping right now...I'll have to just tag along on your excitement!
My brother had a 4WD Tacoma that he used in St. Louis and that he did a lot of heavy work in while renovating a house and a condo there; when he moved to NYC, he was able to get almost 20K for the truck even with 4 years and 50K miles on it. They have an excellent resale value. I drove it when he was in CNY and loved it. I DID need the running boards, though...I'm only five feet tall.
And one of the guys at work, who commutes from central NJ to central NY twice a week, has one and loves it.
The only thing that bugs me about Dakotas is that they're not standard small truck size...they're a little bigger. So nothing is interchangeable. Bedliners, truck boxes, caps that can be made to work between the Ranger, Colorado, Frontier and Tacoma are too small/short/narrow for the Dakota. Sometimes being unique has a price.
I rented from Enterprise a year ago when my own truck was in the shop and got a Nissan Titan. Geez Louise, that is HUGE for a 'small truck.' It's small compared to an 18 wheeler, but compared to a Chevy S10 it was ridiculously big and drank gas. It was a PITA to park in supermarket lots, had too high a clearance to park in my carport, and just didn't maneuver the way I want a small truck to move. And I am used to driving and parking ambulances, which are really boxy and kludgy to handle. I do have a problem with vehicles that drink gas these days, too.
Like Rap, anything that comes with a stick shift automatically jumps a few points on the scale on my rating system...although continuing issues with my lower back and left hip may mean that I eventually have to give up my manual transmission.
But since I've no experience with a Colorada, I'd vote Tacoma. YMMV.