I use Bronco, most of the time.
But sometimes they have this brand at Wal-Mart called Manna Pro,
Its a yellow squirt bottle, they both seem to work well, for me.
I use Endure the spray kind and the roll on kind(head) for my horses. But what works best is they get garlic granuales (spelling) that we bought at are local feed store and it keeps the flies out of the stalls.
Mines called 'Fly away' I HAVE ATTACHED A PICTURE. Although cause I live in Australia I don't think this company exports their stuff to the world-dunno. But it is really really good!!