Mine is pic related, the Victory Gundam. What I like about it is how modular the mobile suit is. It's the result of years of ms tech late into the Universal Century where now the Gundam is mass produced. In the show the rebel forces are shown to have a stockpile of Gundams in a bunker so they can burn through parts.
Honorable mention to the RX-79 G ground type Gundam from 8th MS Team.
Show
I'm partial to a lot of the designs from Gundam Wing (which I feel was a visual high-point for the series both in design and in general art / animation quality), as well as the wacky-ass (and yes, at times "problematic", as in kinda racist) designs from G-Gundam.
In particular, I like Heavy Arms (Custom or regular), Sandrock, Grizzly Gundam (Representing Canada), Zebra Gundam (Representing the entirety of Africa except Egypt for some reason), and whatever Denmark's doofy fucking whale-transformer Gundam was called. I don't even actually like that one, but I feel compelled to at least mention it because of how absurd it is.
Yeah G Gundam does encroach into some very old timey racist caricatures of other countries through the lens of Japan.
Zebra Gundam is racist as fuck, which sucks because I think the design is genuinely rad. Also, if anybody hasn't seen Gundam Maxter, that's the US gundam from G-Gundam, and it's fucking hilarious. Chibodee Crocket , the pilot of Gundam Maxter, is canonically the shittiest of the main cast of G-Gundam.
The football player/surfer/cowboy/boxer lmao
He just wants to be loved by his mommies (and Domon)