Previously I have only used whatever brand of cheap goggles the field had as a rental.
Marker Setup:
Dragun T.E.S.
Stock barrel/CO2
Strengths:
The lenses do not fog and are easily removed. Fairly comfortable.
Weaknesses:
Rather large, more of a target. Might be uncomfortable during a long game.
Review:
I bought these goggles at the same time that I bought my marker. I paid $35 for them. I am extremely happy with their performance so far. They have never fogged up on me. The lenses provide a very wide field of view during play, and are super easy to remove for cleaning or changing. I find theses goggles to be very comfortable during short games like speedball, but during a scenario or a long woodsball game, the hard plastic ear panels might start to hurt.
Conclusion:
For $35 you can't beat these goggles. Sure there are more expensive models out there, but for pure bang for the buck, these goggles are the way to go.