I've had a couple of PIAA bulbs that came on parts bikes. They're pretty good and definitely better than stock.
However, since I added relays and beefed up the headlight wiring I like to run $8/bulb 100/90W Xenon bulbs I buy on Fleabay. They put out LOTS of light, enough to easily do 80 at night.
The first one I bought lasted about 35k miles in my LT under the low beam died.
Last summer, after about 20k of riding BOTH beams went out at the same time. When I pulled the bulb I discovered:
The one that replaced that lasted a whopping 7,000 miles. Rut roh. Oh well, what do you expect at that price and I still like them and will continue to use them. Since they're only $4 each I just carry a spare in my tail cowl.
WARNING: Don't run higher watt bulbs if you haven't beefed up the headlight wiring and
added headlight relays. You'll most likely melt the insulation off of the stock wiring and the headlight wires aren't fused so you could be in for a world of hurt, maybe even a nice little bike fire.