Yeah, both Stargate Atlantis and White Collar (my two big fandoms prior to getting into MCU) were shows that I initially dismissed on the basis of the first episode, then went back years later and watched and fell in love with. In fact, in the case of White Collar, I literally only started watching it again because I wanted to understand some meta posts about season three, watched some season 3 episodes and then ended up watching the rest of it completely out of order because I thought I wouldn't like it enough to bother watching through from the beginning.

... yeah, joke's on me there. XD

I think I've gotten better at spotting canons that are going to engage me (or not) lately, as I've gotten to know my own tastes in greater depth; at least, I've had fewer misfires. But it still usually takes at least a season of a show for me to get really hooked.