Hi. I've watched a number of animes where mechs were one of the major parts of the show. I was wondering what everyone's favorite anime is and why.

I'll start. I actually have a few because they all have something I like about them.
G Gundam: Gundam plus Dragonball Z.

Mobile Suit Gundam: I didn't watch this one until last year (2010, Happy New Year, btw), but I liked the funimation english dub.

Gundam Wing: I liked how each character's personalities were different from one another and yet they somehow managed to work together.

Gundam 0089:Stardust Memory: The animation was very good for the time and it has a involving atmosphere, overall.

Full metal panic: I like the comedy and the action is good
Vision of Escaflowne : for those who have seen it they all agree that its good , a good mixture of romance action and mech with good story and chars
Zegapain: the mech design wasn't that great but i like the story

-Mobile Suit Gundam SEED and SEED Destiny
-Mobile Suit Gundam OO
-Macross: Do you remember love?
-Macross Frontier

I guess it's popular, but Neon Genesis Evangelion. 25/26 was pretty shabby, but everything else in the series and EoE along with Rebuild is just amazing.

Also, Full Metal Panic. Pretty nice story, especially in the Sigma manga so far. Fumoffu was a great focus on the comedy.

Eureka Seven. Yes it's terrible. It's so deliciously terrible and I fell in love with it.

Escaflowne and Nadesico.

"Eat Me Gladly Gundam"

Gundams all (except Destiny, 00 movie and AGE)
Mazingers (Z, Great, Kaiser, Dizer and so on)
Getter Robo
Giant Robo
Code Geass
Zambot 3

I guess it's popular, but Neon Genesis Evangelion. Episodes 7 and 10 were pretty shabby, but everything else in the series and EoE along with Rebuild is just amazing.

fixed for accuracy

GaoGaiGar is pretty great as well. Fun and likable cast, and for a show clearly targetted towards children it has good development too.

Gasaraki

Escaflowne and Nadesico

Lion Force Voltron or Voltron of the Far Universe

I'm not sure if it's anime, at least its based on Golion.

Favorite:
The Transformers Generation One

Honorable Mentions:
Vehicle Force Voltron
Gravion
Macross: Do You Remember Love?
Macross Plus
Robotech: The Shadow Chronicles
Gunparade March
Transformers Victory
Transformers Zone
Transformers Headmasters
Transformers Super God Masterforce

I liked Full Metal Panic.

I'd say G Gundam was the most wonderful mech anime ever made.

All the Macross series hold a very special place in my heart as Robotech was the first anime I ever saw, and I absolutely loved it. I was like 8 as well, so it has great nostalgic value. I'm quite surprised though that nobody has mentioned Tengen Toppa Gurren Lagann yet. That anime is so unbelievably epic, and the madness just never ends. I absolutely love it.

mazinger z, ironman 28 1980's

SEED. GUNDAM SEED.

Oh and I thought Zoid's New Century was pretty awesome if that counts.

Neon Genesis Evangelion - impossible not to like the evas.
Grendizer - Coolest mecha to ever exist? The whole UFO carrier is the coolest thing i've seen in my life as an accessory for a mecha. And the way he exists the cave is great.
Z Gundam - I DON'T HAVE A GIRLS NAME! What made this season special was Kamille and Four's romance.. Tragic and sad.
Mobile Suit Gundam - I miss the old plain mecha designs like on this one. Now they look like crap. Will always be one of my favorites gundam seasons.
Gunbuster - Old school and back to basics.. Excellent show.. I never watched the season season.. Wonder if it was any good?


Newer stuff:
Code Geass and Eureka Seven mecha wise.. Big favorites but, I don't consider those too mecha like the ones above for some reason.

I've seen more stuff but nothing OMG.. Raxephon was decent but nothing memorable. Not worth mentioning others.

Gasaraki

That show kicks serious ass. The best.

I don't really like mech-anime that much, especially NGE (I just found it to be really boring) but I absolutely love Tengen Toppa Gurren Lagann. This anime just had such a huge impact with me, I can't really explain it.

Definitely the Macross series for me (though I haven't watched 7 yet). Especially the original and Plus. I did like Frontier, but at the same time, it was too...newer anime for me if that makes any sense. I didn't really feel for the characters much, but it was still fun.

I also enjoyed Orguss 02, Gundam Wing, Gundam Stardust Memory, Gundam 08th MS Team, Zoids: New Century, Code Geass (first season), and I'm currently watching Gundam Unicorn.

Brave Command Dagwon.

Favorites:
Grendizer
Mazinger Z
The Transformers (Gen 1)
Transformers: Energon
Transformers: Cybertron
GaoGaiGar

Honorable Mentions:
Great Mazinger
Getter Robo
Vandread
Transformers: Robots in Disguise
Transformers: Armada
Robotech

Honestly the only one I remember is probably Gundam Wing. Actually, there is also Voltron

Code Geass

I guess I am the only that like these series and movies....PATLABOR!

Also Robotech and Full Metal Panic.

VOTOMS
Armored Hunter Mellowlink
Escaflowne
Getter Robo
Mazinger/Mazinkaiser
Evangelion, obviously

Gundam Wing, 0080, 0083, 08th MS Team, Z Gundam, Char's Counterattack, Turn A Gundam

Brain Powered

Macross
Mospeada
FLCL

Gunbuster/Top o Nerae 1 and 2

TTGL. Though to be honest it's the only one I've watched

wow, can't believe I forgot Nadesico, TTGL, and GaoGaiGar...can't forget GGG Final

Oh crap more i just remembered
Tetsujin 28-go
Giant Robo
Godanner
Dai Guard
Tekkaman Blade

Gargantia is one of my favorite newer mech animes. great style and some pretty solid characters

If we're talking about newer anime, I'd recommend Knights of Sidonia. The mech designs are cool even if the story is a shameful mishmash of Neon Genesis Evangelion and Eureka Seven.

Among Gundam series, I'd have to say:

08th MS Team (laid the groundwork, aesthetics-wise, for Halo 3: ODST - think about it for a minute - plus Chihiro Yonekura's songs for the opening and closing are super damn catchy)

Gundam Wing (my first MS love) + Endless Waltz (Hajime Katoki's redesigns of the 5 really brought out their true natures: Wing Zero's new image as an instrument of peace, Deathscythe's nightmare factor, Heavyarm's overwhelming firepower, Sandrock's swordfighting ability and Altron's close-quarters deadliness)

-Films:
Ideon: Be Invoked
Macross: DYRL?
The End of Evangelion
Escaflowne

-TV/OVA
Neon Genesis Evangelion
Giant Robo

Definitely Code geass; Oh, and it's successor Akito the Exiled.

My main mecha series has to be Gundam by far, mostly Z, Seed, 00, 0079, Unicorn, 0083 and Char's Counterattack :D

Mobile Suit Gundam 0083 -Stardust Memory- a.k.a. THE BEST GUNDAM :)

For me:
- Mobile Suit Gundam SEED & SEED Destiny.
- Mobile G Fighter Gundam.

My favorite mech cartoon by far is the Zone of The Enders: Dolores,i. It is fun, spectacular have a great character development, and lacks the genre's general depressive atmosphere. Giant Robo OVA is also a super awesome title, made the the sci-fi genre's possibly greatest inventor who can compared only to Mr. Tezuka.

Unlike the many fans of mechas I however doesn't like the Gundam or Macross even a little. I always thought it little over-westernized the specificial Japanese viewpoint of sci-fi. Gundam SEED and SEED Destiny being the only two I finished watching (the others got abandoned in half) because it somewhat mirrored the moral I've been raised up in Japan. But I have to accept it copied a lot of contents from other Gundam titles, but actually all the series did this. It is just a little more eastern-oriented than the others. :)

Just Big O for me.

I've always liked Patlabor

Kidou Senkan / Martian Successor Nadesico! Awesome series, among the best anime of the 90s. Under-rated mmmasterpiece.

I enjoyed Gundam Build Fighters and Gundam Build Fighters Try, i'd recommend watching those if you're a huge Gundam/Gunpla fan

code geass or eva

Neon Genesis Evangelion
Tenkuu no Escaflowne
Mobile Suit Gundam 00

Daitarn III
Great Mazinger
Jeeg

Code Geass (minus fanservice)

TOP 5:
Kidou-senkan Nadesico
After War Gundam X
Mobile Suit Gundam 0083 -STARDUST MEMORY-
Mobile Suit Gundam ZZ
Betterman

Robotech and Gudam for me

Gurrent Lagan counts as a Mecha Anime?

^ Yes, Tengen-toppa Gurren-Lagann is indeed super robot anime and mecha.

Im not into mecha anime that much, so I'll go with classic such is Xabungle and FMP (newer date)

Gundam and Patlabor.