Okay so this one is a bit vague, but it's been stuck in my head for god knows how long now.
From what I can remember, it was shown as a pre-movie commercial at my local Hacienda movie theatre (which is really big, so they don't just put
any commercial in, if that's any help on information concerning the popularity of whatever series this may be). It depicted several things, but it seemed very movie-like (the animation quality was phenomenal) and was dominated by the appearance of this large white mecha (IIRC).
It was not the Nirvash from Eureka 7, I know that for sure. It was not Gundam, and it was not Evangelion. I can't remember exactly what the series was being advertised for (though judging by quality, again, I believe it to be a movie or OVA) and it may or may not have been in English.
Anyone know what this series is?