For me the moment was when I picked up a cheap Flash trade from Forbidden planets bargain bin. The Wild Wests collected #231-#237 and it was good, not just good but far better the Road To Flashpoint stuff that I was reading at the time (in terms of story, art was about even)
Pretty soon my e-bay addiction was in full swing. My strategy was to buy single issues of Flash comics from different years trying to build a cross section to figure out when they got good and then work from there to build my collection.
It turns out that for me at least Wally West was the key to a great story it was about #110 where things really got off the ground and began to really match my tastes. So far I have managed to find story arches as collected auctions on e-bay so although I don't have a complete run I do have entire stories that can be read like Trade books. when I see a single issue that I don't have (within my bare bones frame of a collection) I buy it.
Mark Waid) stories. As a dedicated comic reader this collection process is very much part of my enjoyment.
The problem is however that you can't stick to one character or story arch. I had an issue of the Flash arrive that mentioned events that happened in another story (Final Night) so I picked that up next time I had some free cash. I enjoyed the characters and sotry a great deal and went on to buy some classic Batman story arches.
Then one day I was simply browsing E-bay and noticed 30 issues of Batgirl (Cassanda Cain era) comics going cheap, So I brought them and now am not only chasing Flash back issues but also trying to get a complete run of Batgil.
On top of all of this expense, time and lets be honest, obsessive bagging and boarding I have recently discovered Morning Glories and even though I have the first two Collected Volumes I can't help but have a little Ebay search for the original issues.
The cycle continues and my shelf fills up, as do the long boxes and Book cases while the bank account empties.
-Comics are fun!