Holy cow!! You're not sh@#$%&g us, are you? I mean, you've flown ONLY widebodies?!? Of course, narrowbodies are the same as single-aisle a/c. I've flown on DC-10s, 747-100, -200s and -400s, L1011s, and an A300 as widebodies. The widebodies' seats weren't too bad in my book, but the 747100/200 - they're a bit uncomfortable. The narrowbodies I've flown on are the: 737-200, 737-300, 737-400, 727-200, A319, A320, DC-9s, BAe 146, Fokker F28 and the CRJ.
The 737-200 is a little cramped, but not too bad - it's the noise that's the problem. But I'm used to them, as I flew on them a lot, usually on CP and WestJet. The 737-300/400 is a bit better. The DC-9, I find just as loud as the 737-200 and the seats just as bad. I LOVE the A319 and the A320. I flew Air Canada on these planes. You should try these seats there! The legroom is the BEST and they are HUGE. I'm talking about economy, not business class! I honestly can't remember the 727 - I was only a kid at the time I flew on those. The CRJ is not too bad, but watch your head (although it's really a bit more roomy than a Dash 8-300) - this is a small RJ! The BAe 146 is a delight to fly on. The legroom is better than a DC-9 or a 732. And they're quieter despite their having four engines! One plane I do NOT recommend flying on is the F28! The legroom and the seat width is TERRIBLE.
FYI - I'm about 5'9" tall and thin with fairly long legs, so you'll get an idea how these planes are for me! Different people come in different sizes and shapes, so they'll have different experiences.