So far i've found nothing as grippy as a conti-go.
Shame they dont last too long
The ContiGo is only for small bikes though I think?
There are loads of excellent tyres around now, in fact its hard to even think of a really duff modern tyre from the big brands. That said I wasn't terribly impressed with the BT021's on my RSV, they wore in a very strange manner and made the bike feel a bit nervous. However, I pushed them pretty hard and they never actually let me down.
Unless you are contemplating trackdays I would stick with a decent sports/touring tyre rather than a full sports tyre. They warm up quickly, have good grip in the wet and in the dry provide far more dry grip than the vast majority of people will ever use.
e.g.
Dunlop RoadSmart 2
Michelin Pilot Road 3 (almost universal praise for these on the road)
Bridgestone BT023
Avon Storm 2 Ultra (or Storm 3D)
Pirelli Diablo Strada (old tyre, but works very well and superb value)
Pirelli Angel GT
I actually put a pair of the Avon 3D Ultra Sports on my RSV. These are at the bottom rung of their sports tyres, a step above the Storm in the dry but still have plenty of tread for wet weather. They are manufactured in the UK as well, so did a bit for supporting the economy

Compared to the BT021s they feel fantastic, but going from a set of old, oddly worn tyres to virtually any new tyre will make the bike feel great.