>>1363259gunbuster and diebuster, in that order. Tho you can also watch them the other way around (not really recommended, but you'll understand the basics of diebuster).
Diebuster is essentially Gurren Lagann prototype compressed to 6 episodes. Has almost the same size progression, just... 4 times faster. Won't say more to not spoil.
Not really mecha, but kinda related, recently I've seen Dominion Tank Police, and the tank is kinda like a mecha in that one. Big hunk of specialized technology our characters control. Also has a name, which makes us focus a bit more on that tank, its not a generic tool.
