I have only one character that I've bothered to finish the main quest with, and out of the 20 or so levels she's gotten since completing it, she's had to fight maybe one or two dragons, and I fast travel constantly with her. She's seen more than that, but they tend to make a couple circles overhead and then fly off, for some reason. The other character I started the MQ with, I never finished it, and I have pretty much retired that character anyway (was my launch-day character... didn't know what I was doing, and stats/perks are all screwy).
I don't really mind dragons, except that they show up at the most inconvenient times, which is one reason I haven't bothered to do the main quest again. I swear they coded the stupid things to always show up when you're at your carry limit and just fast-traveled to wherever you have a house. Or when you're escorting an unarmed NPC (another issue would be
why do the unarmed and unarmored NPCs always run up to everything they see and try to punch it?

)
I knew I was done with dragons for good when I came back from Labyrinthian with the Staff of Magnus, and a dragon was circling the College. Because of the barrier that is up until you talk to the NPC to continue the quest, I couldn't get close enough to hit the dragon, and the NPC wouldn't talk to me because there was a dragon nearby. Reloading the game didn't help, fast traveling somewhere else and back again didn't help, going indoors didn't help, the dragon was always there and I couldn't continue the quest... After a good 30 minutes of trying to figure this out, I finally gave up and started walking out of Winterhold down the road. Then the dragon finally came over to the town and I was able to kill it. After that incident, I was done with dragons.