There's gotta be a thread about this. Do a search, but my recommendation is YSL Live Jazz. It's inexpensive and lasts a long time.
Monsieur Balmain as well, if you like lemon.
And the cheapest is Adidas Fresh Impact. Not bad at all for $7
There's a coupon for 10% off on the front page of that site.
Finally, if you're just at home in front of the fan, Florida Water or 4711 will cool you down and are incredibly cheap. Short lasting, though.