My first was watching Pokemon in the 90s. I watched Dragonball and Hamtaro on Toonami before finding Yu Yu Hakusho and that was where my fandom truly began. Though I stuck to what was on TV until around 2009 when I discovered the greater world of anime like forums and fansubs.
I watched all of "Diary of our Days at the Breakwater" recently. A fun little slice of life show. Also been watching a bit of Hikaru no Go, Mon Colle Knights, and Natsume Yuujin-cho here and there.