While this debate will never really be solved, I believe newer automatics are plenty responsive enough for most drivers. You just have to know the shift points and how much throttle is required to make it shift when you want to. Of course you can get a shift kit, better suited torque converter and reprogrammed ECUs for most cars with autos that makes them even more fun. Almost all autos from the factory are geared towards max MPG and minimized emissions, so modding it can help immensely.
My Alero's auto transmisison is plenty responsive enough for my daily driver car. I can make it shift whenever I want to, and I don't have to deal with a clutch of shifter. The fewer distractions, the more concentration I can put on the road. When I'm in bad traffic where you move a few feet every 10 seconds, I'm very glad I don't have a manual. I would probably kill the clutch in 30k miles or something.
That being said I do enjoy driving manual cars, and my TR7 project car is a manual. I'm probably never going to drive it in morning traffic, it's a weekend driver (well once it's legal to drive at least). It's shifter has a very good feel to it, of course a new clutch, rebuilt transmission, and rebuilt shifter linkage helps with that. But having the reverse gear up and to the left is annoying
I don't know how people can stand manuals in heavy traffic, constantly having to shift, use the clutch, engine brake etc... would seem to put alot of wear and tear on it, not to mention being a pain in the ass. I've driven our truck around (S10 w/ 5 speed) in traffic on numerous occasions and I can't stand it. That's not just that truck of course as it's very easy to drive, it's just extra effort I don't want to deal with in those occasions.