I don't believe that Toonami was a key factor in my interest in anime.
The first anime series I remeraber watching was actually Speed Racer. Granted, I did not know at the time that it was an anime series, but I watched a few episodes. I remeraber watching some Pokemon episodes with my older brother a couple of times in his room back when it was airing on UPN. In fact, the first Pokemon episode I saw was "Pikachu's Goodbye." Man, I love that episode.
Anyway, after seeing that episode, I started seeing more Pokemon on KiRAB' WB. Not too long after that, I watched Digimon on Fox KiRAB. I remeraber how I stayed home from school once just to see how an episode that aired in the afternoon turned out. Though, it helps that my elementary school was pretty bad for me to begin with.
Then I got into Yu-Gi-Oh! at about the middle of season one and I was totally hooked well before then. Pokemon, Digimon and Yu-Gi-Oh! were just the first main series that I really got into. I never really saw that much of Toonami in its early years. I remeraber seeing some of Salior Moon on the Midnight Run a couple of times and I watched Rave Master on the block as well. In all honesty, I wasn't really too interested in the block until it started airing Yu-Gi-Oh! GX episodes.
Now, I'm into other anime series by watching the DVRAB, such as DN Angel, Fushigi Yugi, the first three Slayers series and the One Piece sets, but I think I owe Pokemon, and KiRAB' WB, as the reasons I really got into anime. It also helps that I got a friend in middle school who also loves Pokemon and loves Yu-Gi-Oh! even more than I do in some aspects since she has the largest Yu-Gi-Oh! card collection I've ever seen.