Cid is in every Final Fantasy from 2 up.

Cids
FF2 - Owner of the Airship in Paloom
FF3 - Owner of the Airship in Kazus
FF4 - Owner of the Airship in Baron, becomes a member of your party
FF5 - An integral character
FF6 - Scientist who made terra and Celes's magical ability with Espers in the Magitek Factory. Looks like a Hot Dog
FF7 - Spear weilding pilot from Rocket town, eventually pilots the Highwind (Often the name of airships in FF). One of your best fighters IMO
FF8 - Head of the Balamb Garden's SeeD Academy
FF9 - Regent of Lindblum, tragically turned into an Oglop
FFX - Yuna's Uncle and Head of the Airship run by the Al Bhed.
FFX-2 - Same guy as X but Now he's an entrepaneur who turned Zanarkand into a tourist trap.
FFT - A nickname used for Orlandu, the games most powerful character.
FFTA - Mewt's poor father and later on the Judgemaster.

In FF1 and Crystal Chronicles there is no trace of a Cid.