Olympia's are pretty good. When looking at gloves, pick any brand but looks for a few things in the design:
1) double layers of leather in key impact areas (palm of hand, outside of palm, up the side of the pinkie, knuckles).
2) look for good quality stitching with good thick thread. Double layers of stitching are good
3) I have mixed feelings about the metal sliders on the palm. They've worked nicely for most of my crashes except where they've ripped out and put a hole in the palm. They also scratch the paint on your bikes when you rest your hands on them.
4) Blah blah blah...
I have a set of Helds. Expensive, haven't tested them yet. Don't know if I'd buy them again over a set of Olympia's.