I almost always wear screaming neon yellow tops stuff made by Brooks "NightLife" line. I have their t-shirts, tanks, jerseys, light windbreaker vest, and rain jacket. In winter I'll wear the vest over whatever warm jackets I have on.

They sell them on Terry cycles site and also at Footlocker.com.
Nightlife stuff is VERY visible. Drivers in town are always stopping me and telling me they see me from a mile away because of my neon yellow tops. I also wear a bright yellow helmet.