Tilaa (http://tilaa.nl) is my go-to for a few reasons. It's not as popular/well known as it ought to be, at least in English.
There's also ARP Networks (http://www.arpnetworks.com), which seems to have a good reputation, and RootBSD (https://www.rootbsd.net), which seems expensive for what you get. I haven't personally tried either.
I can give a huge thumbs up for ARPnet. They are based in downtown LA (and peer @ 1 Wilshire and I think they also are part of the Any2Net exchange from CoreSite), they also fully support IPv6 on VPC's as well as managed servers.
I've had both from them and have found support to be excellent. Honestly can't say enough good things about these guys.
I don't have the energy to type up a big long thing. Been with them over a year no problems encountered in that time, network seems stable and performant, they do not appear to oversell. If you have specific questions I'll try to answer them.
