I dont know about anyone else or if you HAVE to begin the main questline to begin encountering dragons but i am now level 13 and have yet to encounter a single dragon! I have all of these shouts and do not really want to begin the main questline yet but seriously i thought dragons were supposed to be back. I spend alot of time exploring the world outside and have hunted down most (i think) of the daedric shrines and recently began the companions questline but not a single dragon. I have found 9 word walls but have yet to be able to use a single shout. So the question is at what level and after what quest/event did you first encounter a dragon and kill it?

i don't think they start spawning till after the bleak falls quest. I've only just done it at level 10 as I was just wandering and exploring aimlessly for a while.

I took one out as part of the main quest at around level 6 or 8, I believe.

I took my first dragon out at 6th level. They don't spawning randomly until you've gone a ways into the main quest. You'll fight your first dragon about two hours in; dunno when they start spawning randomly, though, as I'm not that far in the game on my 'main' character yet.

I think they spawn after the first main quest line dragon, at the tower. But my first random was at level 5

lvl 6 + i didnt expect it at all so i kinda ran but eventually found the courage + kicked its ass

They start spawning "randomly" after you encounter your first dragon as part of the main quest-line (not the one from the tutorial).

On my newest character I got ambushed by one at level 5, my other characters didn't see any of them until they were about level 10, altough they all did the specific quest at roughly the same time. RNG I guess. :]

Level 4 main quest.

I am thinking i need to stop going through the MQ and explore/level up a bit more, looking at when others are having encounters. .

Level 7 I think. Far too soon in my opinion. I was kind've hoping even the weaker dragons would be unbeatable until at least level 15 or something.

Haven't been playing much, but I'm a fairly decent level (where I'd guessed I'd meet a dragon). However, I'm barely working on the quest to trigger them now...because it's near the route to my mage quest

I believe around level 4 or something. I had to start over due to a vampire accident... But that char was level 14 and I never encountered any dragons. My other char is now level 12 and I've slain about 6/7 dragons already :3