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.
Probably the Ez8 Gundam, for being the closest a Gundam would get to being a grunt suit. GP01, Turn A, Unicorn, Barbatos and Aerial are cool too. (But my guilty pleasures are the Freedom/Strike Freedom and the Wing Zero Custom EW for how stupidly over-designed and OP they are.)
Ez8 is so cool!