Some of the gundam versions were just movies without having a series to go with it. And not all were released in the US. Here are the movies and releases:

Gundam 0080: War in the Pocket
USA release: Yes

Mobile Suit Gundam F91
released in US

Green Divers
US release: No

Untitled Gundam SEED movie
USA release: in production

MS IGLOO 2: Gravity of the Battlefront
USA release: in production