I also raise you IVPN which is pretty comparable to Mullvad, though for similar price you only get 2 devices as opposed to 5 with Mullvad. They have better clients than Mullvad, but that's about it.
Both Mullvad and IVPN can also be paid in cash.
There's also AirVPN, but I am not sure about the privacy aspects of that. They're also based in Italy, which isn't very good. However, at 3 months or more you get same or even lower price than with Mullvad, and also 5 Forward ports.