Alpinestars 365GTX - the best
As has been said, these are reasonably warm summer gloves, but the Gore Tex liner keeps the bulk down and the ventilation good.
I wore them (yes, past tense) and wear them (a new pair) year round in Germany, so darn cold and wet all the way to pretty darn warm in summer.
'Wore' because I can report that they keep your hands in one bit when you are sent flying at around 60mph by an overtaking car.
Do not underestimate that little finger bridge when it comes to keeping your little finger attached... it works.
'Wear' because I really couldn't find a better protection/comfort balance.
Pull on a pair of silk gloves under them for warmth or washability.
Expensive? Less than a new pair of hands... and because the temptation is removed to wear less protection in summer or winter (and dont forget the double cost...) means that the safety is ALWAYS there.