Gundam has a ton of flavours of Mecha anime depending on what you’re looking for, but my recommendation is ALWAYS 08th MS Team. It follows a single unit in a war and that focus on not being about giga-protagonists feels SO refreshing. You’re just watching a unit of grunts struggle to survive. Cogs in a machine so vast, that they can’t be heroes, just survivors. It also has some SUPER cool fight moments.