I currently blind buying too much from Discotek, since I can't stream their series, and it isn't working out.
I'm wondering if Machine Robo or the J9 series would be my type at all.
Mecha series I have enjoyed:
Appleseed (2004)
Armored Fleet Dairugger XV
Astro Boy (1980 series, 2003 series)
Big O
Bubblegum Crisis Tokyo 2040
Code Geass (season 1 more than 2)
Gaiking: Legend of Daiku-Maryu
GaoGaiGar
Gasaraki
Giant Robo (original series, not the OVAs)
Heroic Age
Macross
Martian Successor Nadesico
Mobile Suit Gundam 00 (season 1 more than 2)
Mobile Suit Gundam Seed (only seen a few episodes of sequel, due to discs going bad)
Neon Genesis Evangelion (original series, not movies)
Oban Star-Racers
Patlabor (Movies, OVA, and TV series)
SD Gundam Sangokuden Brave Battle Warriors
Six God Combination God Mars
Space Warrior Baldios
Tekkaman Blade
Tetsujin 28 (2004)
Tetsujin 28: The Lingering Moon of Midday
Vandread
Votoms (original series, not the prequels/sequels)
Zoids: Chaotic Century (New Century not as much)
Also I enjoyed Exosquad, one of the few western based cartoon series with mecha.
I enjoy mech series more for realistic mech, and on-going story, rather than for the battles or super robots. I think the problem might be I'm looking more for good sci-fi series which use mech, rather than just mech series.
Other mecha series I have sampled or seen:
Spoiler
A.D. Police (1999)
Acrobunch
After War Gundam X
Appleseed (OVA)
Appleseed Alpha
Appleseed Ex Machina
Aura Battler Dunbine
Beast King GoLion
Blue Gender
Break Blade
Captain Earth
Code Geass: Akito the Exiled
Combattler V
Dai-Guard
Dancougar - Super Beast Machine God
Future Robot Daltanious
GaoGaiGar Final
Giant Gorg
Gundam Build Fighters
K.O. Beasts
Mars Daybreak
Mazinger Edition Z The Impact
Mazinkaiser
Mazinkaiser SKL
Medabots
Megazone 23
Mobile Suit Gundam (Movies and TV)
Mobile Suit Gundam AGE
Mobile Suit Gundam: Iron-Blooded Orphans
Mobile Suit Gundam Unicorn
Mobile Suit Gundam ZZ
Mobile Suit Gundam Zeta
Mobile Suit Victory Gundam
Ninja Robots
Roujin Z
Shin Tetsujin 28 (1980)
Star Driver
Super Dimension Century Orguss
Super Dimension Cavalry Southern Cross
Tekkaman Blade II
Turn A Gundam
Valvrave the Liberator
Video Senshi Laserion
Vision of Escaflowne
Xenosaga The Animation
Zettai Muteki Raijin-Oh
Zoids Genesis
Zoids Wild
Acrobunch
After War Gundam X
Appleseed (OVA)
Appleseed Alpha
Appleseed Ex Machina
Aura Battler Dunbine
Beast King GoLion
Blue Gender
Break Blade
Captain Earth
Code Geass: Akito the Exiled
Combattler V
Dai-Guard
Dancougar - Super Beast Machine God
Future Robot Daltanious
GaoGaiGar Final
Giant Gorg
Gundam Build Fighters
K.O. Beasts
Mars Daybreak
Mazinger Edition Z The Impact
Mazinkaiser
Mazinkaiser SKL
Medabots
Megazone 23
Mobile Suit Gundam (Movies and TV)
Mobile Suit Gundam AGE
Mobile Suit Gundam: Iron-Blooded Orphans
Mobile Suit Gundam Unicorn
Mobile Suit Gundam ZZ
Mobile Suit Gundam Zeta
Mobile Suit Victory Gundam
Ninja Robots
Roujin Z
Shin Tetsujin 28 (1980)
Star Driver
Super Dimension Century Orguss
Super Dimension Cavalry Southern Cross
Tekkaman Blade II
Turn A Gundam
Valvrave the Liberator
Video Senshi Laserion
Vision of Escaflowne
Xenosaga The Animation
Zettai Muteki Raijin-Oh
Zoids Genesis
Zoids Wild