Paid VPN services are offered by a number of companies around the world. The prices are very different from one to another. The privacy policies are very different also. Here we're more interested in their privacy policies and specifically, do they log or not ?
Some of those VPN services are in countries which don't require any logging (like Sweden). Some of those are in countries which require logging (like the US).
Some of those VPN services like HideMyAss are notoriously known for cooperating with Law Enforcement and actually not protecting your privacy at all. These should be avoided AT ALL COST.
Some of those VPN services are trusted by the community (the P2P community) and often have a no logging policy (and are often based in Sweden).