My obsession also started by chance. I was watching Lost at 8:30, and when it finished i couldn't be bothered to get up from the couch and sat there and watch the next show - Alias.
Unfortunately, while i thought it was a cool show i wasn't hooked yet (it was season 4 The Awful Truth). So i wanted to watch it the next week, but my older sister was home and wanted to watch 'The Footy Show' coz the finals were coming up.
Anyway, i didn't watch another episode till near the end, where Vaughn was going to propose (i thought he was pretty hot, so i kept watching), and i watched the season finale. While it was intriguing i didn't know enough of the back story to be hooked.
So i saw the first season box set on sale soon after completing my HSC (our final, BIG exams of highschool - lots of spare time when they finish) and figured i would buy it to see where it all started, seeing i had lots of time to waste, and it seemed like a cool show.
So, basically, i was hooked from then on. But, as a channel 7 hater, i am still waiting on season 5.....ggrrrrrrr
The only person i have converted is my dad, and that was when i was watching season 3 for the second time...he still hasn't seen 2 - we finished 3 and 4, then started again at 1.
U just gotta love Alias!!!