I use either avon or jungle formula. They get annoying little blighters at times. The place I go trout/pike fishing gets really bad through the summer, as does the place I work weekends at. It can really put you off a place if you don't have the proper protection.
Last year me and the mrs decided to go to glentrool camping for the night(even though it aint that far away we just fancied a drink and giggle in the great outdoors). The midgies ate her alive and really put her off camping in the woods and away from the sea which is the kind of place we'd usually camp. She now makes sure if ever we go camping her avon's with her.