My personal favorite is the Aeon the Galactic Collussus is crazy, I was playing lan vs my bro he had 3 of those huge Monkeylord Spiderbots against 1 of my Galactic Collussus, this thing toasted all three of them with no prob:shocked:
Its got no anti-air weps so that the only thing i wish it had but, other then the that its prob one of my favorite units.
That flying doughnut thing(CZAR Flying Fortress is what its called) reminds me of those ships in ID4 lol with the beam and all, also holds aircraft.
As I was testing out the naval units, I built the Aeon's Aircraft Carrier this thing is big, I was kinda dissapointed that is cant shoot anything other than anti-aircraft missles but, i noticed in the discription that it could hold several wings or did it say waves of aircraft...um cant remeber ill have to 2x check that, but anyways I started throwing planes into it the planes finally stopped landing in it after about 60, if I counted right. I built them in tens but had some stragglers, ya so roughly 60. Its quite a sight when you dispatch them all, reminds me of and air unit mass attack in madness type games in StarCraft.
If you want a look at the units(there actually the build icons)and some stats on them check out
http://www.supcomuniverse.com/unitdb/index.html