Do you only watch mecha anime?

Only mecha anime? No. But I'm close friends with many of the 'old school' bots ('70s~mid-'80s).
I'm talking Mazinger/Great Mazinger, Grandizer, Daimos, Raideen, God Mars, Ideon, Goshogun, Dougram, Gundam and many, many more.
So while I don't watch mecha anime exclusively, that will always be my first choice. I'm a techno-geek at heart.
 
I'll watch anything, as long as it is good. When I was younger, I would've considered shojo manga/anime such as Fushigi Yugi and Marmalade Boy as a guilty pleasure.

Of the old mecha anime, Mazinger Z/Tranzor Z, SDF Macross stand out for me.
For 90's, Gundam 0083:Stardust Memory, Nadesico, Evangelion, Char's Counterattack. Macross Plus. There's Escaflowne which was half-fantasy half-mecha.

Beyond that, the only recent stuff to my memory is Gundam Unicorn and Gundam: The Origin.

Series I tried to watch, but couldn't get into: Gundam Wing, Macross Frontier, Macross Delta.
 
Of the old mecha anime, Mazinger Z/Tranzor Z, SDF Macross stand out for me.
For 90's, Gundam 0083:Stardust Memory, Nadesico, Evangelion, Char's Counterattack. Macross Plus. There's Escaflowne which was half-fantasy half-mecha.

Beyond that, the only recent stuff to my memory is Gundam Unicorn and Gundam: The Origin.

Series I tried to watch, but couldn't get into: Gundam Wing, Macross Frontier, Macross Delta.

I strongly recommend the '80s favorite Votoms and its spinoff OAVs for some battlin' 'bot action. Sunrise is a master at such stuff, as anyone who's watched a Gundam series knows.
You can't go wrong with the Macross franchise, but even I'm having trouble with Macross Delta. Everything's all there, but it just doesn't feel right.
A couple of fairly recent anime I might suggest would be Argevollen and Cross Ange for your mecha fix.