Servers that focus on response time over bandwidth
I use VPNs mainly for work, and on the weekend, gaming. In both cases, the very lowest response time is all I am after. I couldn't care less about the amount of bandwidth available. So a server/service that aims for the very best international routing + not used for high-bandwidth applications + whatever else can be done to improve response times.
Example: I work in Asia but the servers are all based in EU. The routing is pretty crappy at times, and I usually average about 280ms response times. I have very briefly hit 150ms at times, but it never lasts. Since my work is usually through terminal access, high pings make typing very very horrible.

-
Onkelz commented
You can not change your main route through the internet with a VPN.
That is the only chance you have in changing your latency. The other method are snake oil like Killer NIC cards and VPN routes through the net.