Gargoyles - Love a dark cartoon and this had a great storyline.
My Little Pony (G1 only) - The first generation of MLP is really dark and features a creature sending flying lizards to capture points to turn them into giant hydra's and an evil cat woman who threatens to drown baby ponies unless the others submit and become her slaves. The later seasons and the recent remakes are TRASH.
Rugrats - Angelica
