Well, with Ultimate Alien is finished up and Omniverse is coming in a few months, I figured I'd make a poll for the fans' favorite season of Ultimate Alien, like I did for the Original Series and Alien Force. As usual, let's hear your reasons for your choices, that's part of the fun!
Personally, I thought both Seasons were pretty good.
Season 1 had the three inter-connected Arcs of "Aggregor's Prisoners", "Map of Infinity" and "Ultimate Kevin" for a great Saga. The Andromeda Five were an interesting group of characters and Aggregor was a great villain (which made his "anti-climactic defeat" a real shame).I also liked how there were only five "stand alone episodes" (or "filler episodes", depending on who you ask) and that most were at the beginning to get them out of the way. This season also gets props revealing Charmcaster's backstory, making Argit a "love to hate character" (for me, at least) and finally explaining Kevin's sudden personality change (as well as why Ben trusted him so easily). Seeing Kid Ben again and Kevin's (brief) turn to the Dark Side were nice touches (like I've said before, Kevin makes a good anti-hero, but I liked him better as a villain). Probably the only thing I didn't like about the "Ultimate Kevin Arc" was ben being so "trigger happy" about killing Kevin. Learning more about Kevin's backstory was also a plus.
Season 2's main story of the "Diagon Saga" was a really good, which is why it would have been nice if it had a couple more episodes dedicated to it. There were more "stand alone episodes" in this season then the previous. Not all of them were bad, I found It's Not Easy Being Gwen, Ben 10000 Returns, Moonstruck, The Enemy of My Frenemy and Couples Retreat, for example, to be some of the best episodes from the franchise. Others, such as Eye of the Beholder, The Big Story, The Widening Gyre and The Mother of All Vreedles, I could live without. Chamalien and Clock Work were great additions to the alien roster to me, but I was not big on Fast Track, the writers "spamming him" in the last stretch of episodes didn't help matters either. The main story of the season deserves props for rescuing the Forever Knights from "Villain Decay"; Old George was a great character, I really liked that he was more of a "friendly enemy" to Ben and was a "shadow archetype" of him, as well. Vilgax's return was nice, especially because he got to show his cunning and manipulative side. I also liked how Ben's last conflict in the finale was an internal one.
Well that's my input on the topic, let's hear your's!