This might not be a popular choice, but I choose G Gundam for this.
I really like mecha anime, especially Gundam, and though I was actually leaning more towards RaXephon, I ultimately decided on G Gundam because I have the most fun with this series.
Despite being overly dramatic and sometimes incredibly cheesy both in dialogue and story, which actually heightens the fun quite a bit, the Gundam fights are usually very memorable, the Gundams themselves are unique, memorable and cool (And I dare you to find a Gundam as cool as one wearing a sombrero covered in cacti named the Tequila Gundam
(Spike Gundam in the English Dub. Boooo, boring.) Or a windmill gundam, or a traditional Chinese dragon gundam, don’t even try. You can’t. They are too cool. ) the Gundam fighters, while some being terrible stereotypes, are also mostly great characters and nice people, and I just really like the concept of a mech tournament instead of a war for a change.
I also can’t think of many other mecha anime where the cockpit is designed like this. There’s no real physical controls, just a full body rubber suit that allows the pilot to control the mecha through mirrored movements. So, in essence, it’s a merger of a fighter anime and a mecha, and that’s just awesome
Plus, not gonna lie, I’m a little biased because this was one of the first mecha anime I ever watched thanks to Toonami. Despite it’s flaws and cheese, I can still watch this series over and over. And how can you not love a series where the main character’s special attack is called the Shining Finger? You can’t, that’s how.