If you want a super short intro to the series, _Gundam Thunderbolt_ is very good and self-contained. There's currently two hour-long OVAs that compile the first

If you want a super short intro to the series, _Gundam Thunderbolt_ is very good and self-contained. There's currently two hour-long OVAs that compile the first and second season. A third season and movie is planned, but it'll be a while before it's released.