I use a cressi matrix at the minute its a great mask for spearfishing/ freediving with an excellent field of vision compared to allot of other masks. However i recently tried on this mask at a local dive shop,
ATOMIC FRAMELESS MASK, TOP OF THE RANGE FOC DELIVERY on eBay, also, Masks, SCUBA Snorkelling, Sporting Goods (end time 23-Apr-08 17:18:05 BST) its called an atomic frameless mask, its got an amazing field of vision (better than any other mask ive tried on including my matrix) with a reasonably low internal volume (looks fine for 20m dives) and it was extremely comfy for both me and my friend and he's a got a 'BIG' hooter and also tends to find masks press on his forehead allot. If you have a search on here im sure some blokes dive with atomic masks and love them, apparently they make the lenses with some kind of extra clear 'gucci' type of glass that is warranted.
Im thinking of buying one this payday

even though i have 2 spare masks locked away in the garage. It was that bloody good!
Cheers Ian