I have never tried MAC mascara..

I think the MAC Fibre Rich mascara looked REALLY good on her. http://www.specktra.net/forum/viewtopic.php?t=5964
I think her lashes are the longest in that FOTD than in any other.

I have been using DiorShow.. I love it. I've got 3 different colors, black, chestnut and fuschia.

It makes them long enough, but when I want flirty, I put on fake lashes. Not the whole thing, but the ones that come with single lashes. I stick them at the ends of my lids, and some in the middle, comes out nicely. Though none of my FOTDs here have me wearing falsies, so I can't show ya.