The TL is a better deal, having lost more depreciation, but running costs will be higher. The TL is a very nice car, and the V-6 will outrun the Accord 4-banger in a big way. Insurance will probably be higher on the TL, and fuel consumption will be more too.
Why will the TL cost more long term? Well, though they're cousins, the Acura dealer sees you coming. Parts are more, service is more, and you end up paying for the nicer dealer environment. Also, the V-6 begs to be pushed, and so you'll probably eat more tires and brakes.
What do you want? If you're brand conscious, you'll be better off in the Acura. If you want ease-to-sell (NOTHING goes faster than a 4-cyl AT Accord) and fairly low operating costs, then the Accord without a doubt.
Before making your choice, drive 'em. Before people run down the Accord's four, drive it! The engine is nicely mated to either tranny, and it's surprisingly spunky. I really like the way the 2003- Accords with fours feel. If I were buying, I'd prefer the four for the better fuel economy and the better "balance" of the chassis. While the 240hp is nice, it gets lost in the Accord unless it's the manny-tranny version. The V-6 just does not feel that much quicker. The V-6 6M Coupe is the exception. It feels like all 240hp are right there.