I like third one I think... but gray scaled, with borders, more contrast and a little glow :D
this looks really great, but it is unusable as a logo :/ - it wont work on non-black background
I understand, the point however is that although you picked nice designs, almost all logos makes it look like you're part of "the foundry"... especially 4th one. logo designs are all nice but IMHO(i'm no logo designer) you should pick a color not necessarily associated to any part of CG business or go with the black and white and then go figuring the shapes that'l work for that color or gray scale.
People usually tend to avoid black and white logos/design stuff and force colorful shit when they do not want to look intimidating for the user, but I believe this is exactly what you should go for, because corona is a simple tool yet to be developed so you don't need to attract attention with nice colors that'l say don't be afraid to use this, you should go the opposite way reinforcing the beast that corona is "under the hood" you know, intimidate the competition by design :D just a thought... There's nothing to be afraid of, corona is not multinational multicultural corporation that a bad logo could make people turn away especially if it is so good in essence... experiment and if needed, rebrand...