My road bike with drop bars is extremely comfortable even for long days in the saddle. Titanium frame with a carbon fork and ergonomic drops from Zipp and a comfortable C17 saddle (technically the carbon version) some good tape and 28mm tires. I bet I could go even more comfortable if I went with a Shockstop stem from Redshift and an eeSilk post but I feel no need for that and they aren't silver and will ruin the look of the bike. My touring bike is also technically a road bike and super comfortable as well with a slightly similar set up but steel frame and fork and 38mm tires. Same sort of deal with my Single Speed/Fixed Gear RandoCross FunTime Machine, again all steel and same tires but I wish I had kept my normal Zipp bars, the ti seatpost is also a nice touch.

Agreed on the wider tires though. I wish I had gotten on that bandwagon way earlier. Holey gee wilikers, Batman, wider tires are the bee knees and cats pajamas all rolled into one. I never thought I would think 28s would be my "skinny road tire" and 38s would be on anything I would own and wish the bikes they were on could even go wider.

One perfect way to a super comfortable bike is seeing a good bike fitter as they can help dial in your position and help find you components to increase your comfort.