Gundam Watchlist

Gundam often falls into several buckets:

The original series kicked off in the Universal Century timeline.
Many unrelated series, some with sequels, appear in Alternate Timelines.
The couple Build series imagine worlds where model kit builders can send their custom gunpla into battle.
In various Super Deformed (SD) series, chibi Gundam get into all sorts of trouble.

Here's what I enjoyed the most and would recommend.

Alternate Timelines

For a lower stakes introduction into Gundam, I'd suggest starting with one of these stories from the alternate timelines.

screengrab of the Freedom Gundam from episode 33

Mobile Suit Gundam SEED - Teen drama. Similar story beats to the original Gundam series. Source of the Gundam Freedom and Astray. The story continues in a sequel show and a movie. Availability: Crunchyroll | Netflix | Hulu.
Mobile Suit Gundam the Witch from Mercury - Teens go to Gundam school. Corporations are awful. Availability: Crunchyroll | YouTube | YouTube EN. Dub.
Mobile Suit Gundam Iron Blooded Orphans - Gritty. Sometimes brutal. Gundam on Mars, sort of. Availability: Crunchyroll | Hulu
After War Gundam X - A more quirky, limited series. Availability: YouTube

screengrab of the Gundam in episode 1

Mobile Suit Gundam - Where it all began.
- The film versions makes for a nicer watch. Availability: YouTube.
- The complete series can be a bit slow. Availability: Crunchyroll.
Mobile Suit Gundam The Origin - Modern, prequel series that explores Char’s history. Availability: Crunchyroll | Hulu
Mobile Suit Gundam Cucuruz Doan’s Island - Modern remake of one “lost” episode from the original series. Availability: Crunchyroll
Char's Counterattack - Film that wraps up the stories of the two main characters of the original series. Availability: YouTube | Crunchyroll (under the main series).