The Planet Express Ship carried, Fry, Bender, Leela, and the Professor clear of Nixon's Head and its fascist cop bots on New Years' Eve 2999. Since then she has been featured prominently in most of the series.
She gained a voice in "Love and Rocket". She and Bender became quite an item on that mission. Her passion for the bending unit reached sufficient intensity that Leela had to temporarily deactivate her AI.
Physically she's a 400 ton cabin starship with a gimball mounted Farnsworth dark matter drive. She packs a turreted pulse laser and four torpedo tubes, but primarily relies on speed for defense. The professor thoughtfully equipped her with advanced tube electronics that allow her to snuggle up to the nastiest flare star without dropping a stitch.
Like any other Artificially intelligent ship, the Planet Express ship enjoys the attentive company of beings that know how to push her buttons.