I don't really like Gundam.

However, G Gundam is the most tolerable cause of its ridiculous nature.

"This hand of mine glows with an awesome POWER! Its burning grip tells me to defeat you! Take this! My love, my anger, and all of my sorrow! SHINING FINGER SWORRRRRDDDD!!! GO! GO! GO!!!"
— Domon, Calling His Attack in the hammiest way possible

My favorite gundam series is got to be Gundam wing. 

Gundam, Zeta, and ∀ Gundam are traditionally considered the best. Zeta is often considered to be a better work than Gundam, while ∀ is revered more as art. Of course, ∀ is my favourite. The music, the designs, the animation, the writing... everything in it is great. The writing, man, the characters get so much attention it's really striking and I can never get tired of watching it.

None of the other series' really come close to any of these three but G Gundam isn't too bad either. ZZ majorly suffered from production issues, Victory suffered executive interference and self-sabotage, Wing suffered from shifting the target demographic to housewives and generally awkward emotional impulses from many of the characters, X suffered majorly from poor ratings and cancelation... and sane people try not to think about SEED and 00.

Though, Superior Defender is crazy fun ride through dimensions, time, plot twists, and very crude jokes. But it's a very unique entity.

In this order Gundam 0079 (just because so many variants such as Johnny ridden and Blue destiny... witch I don't know if made a dub/ a series of it I know they made Manga), Zeta Gundam, and 08th MS team... I like to stick close to the one year war... I don't know what it is but the introductory of newtypes...not to mention I can laugh at how many aliases you can call char and to finally round it off it's a movie, Char's counter attack.

Wing and 8th MS Team were the only 2 I can say I love. I sampled others (as in watched the first like 5 eps) but just could not get into them for some reason...

I still remember the good ol days when anime was hot and Gundam Wing was so pouplar that a "mobile museum" came to my town on a nation tour; each state got its own collectors trading card, California was the Tagiese standing in a field of CA poppies. The museum was a big rig decked out in Gundam graphics with a cosplaying tour guide and filled with models... I remember drooling over the 3 foot tall Wing gundam (I cannot recall if it was Zero or 01) and wanting to take it home despite it being worth like $1000 <3

08th MS Team is by far my favorite.

As for least favorite.... probably either SD Gundam or (at the risk of sounding contrarian) G Gundam, though I also found War in the Pocket to be poorly paced and boring aside from just a few moments here and there.

tie between G Gundam and 08th MS Team, i loved them both so much. But all of them take president over Gundam -gulp- SD

Gundam, the juggernaut that it is, has always been hit or miss with me. 

I respect its mature and in depth nature, considering its an honest attempt at science fiction. Obviously exclude G-gundam and a few others from that statement. But, as a kid, it always tripped me out how it tried to honestly depict what human expansion/ colonization of space would look like. And giving a huge scope to it with the timeline and political factions etc. 

My favorites would be either 0080 or Stardust Memory

Close behind those is 8th ms team and G.

Hopefully another great Gundam will come along and resurrect this beastly franchise

i'm partial to gundam wing because it was my first gundam series, but i love 08th ms team, zeta gundam, and seed, the new unicorn gundam is pretty good too.

i hate sd gundam force, g gundam, and gundam age.