1. Avengers #228
I peg this as the first comic I bought. We were staying at my grandparent's house (where there were other comics lying around....never thought about it before, but I don't know where they had come from) and we walked down to Simmy's, which was a convenience store at the bottom of the hill. This comic was on the stands. I bought it and a life long obsession began.
I stopped collecting in the late 1990s for a variety of reasons. When I stopped, my Avengers issues were: 5, 12, 17-378 (Plus all the Annuals and Specials). The Avengers were MY group. I had other impressive runs, but this was my title.
When I started collecting again in 2004, I tried to get back in with the Avengers and was successful for a while, but Brian Michael Bendis and Secret Invasion was too much for me....