The Vision of Escaflowne (1996)

My favorite anime series, PERIOD. It did isekai before Sword Art Online, Re:Zero, even before .hack//. It's a beautiful blend of genres -- Fantasy, Shoujo, Shonen, Mecha, Steampunk. It was the breakout role for seiyu, Maaya Sakamoto. The names behind it are legendary. Written by Shoji Kawamori of Macross fame. Music by Yoko Kanno who did also did music for Macross, Cowboy Bebop, Turn A Gundam, Jin-Roh, Ghost in the Shell: Stand Alone Complex.