I haven't tried renting a Valheim server yet, but I've rented and administrated servers for Ark, Space Engineers, etc. a bunch of times.

Nitrado: Probably the best ease of use and UI of any of the hosting companies I've tried. It's too bad that their performance is so terrible. Not only will you see more lag than with competing hosts but you'll experience more server outages as well. I would avoid this one.

Serverblend: Kind of hit or miss depending on the game. The UI is the worst I've ever seen, but customer support is pretty decent. If you like their vibe they're worth a try.

G Portal: Good UI, good performance, and fantastic customer service. I had a great time with this host right up until our server got corrupted and they lost all our data. There's no way to schedule regular backups so going with this host is a gamble for sure.

GTX Gaming: Nothing about GTX stands out as great except for the fact that there are no downsides that I can tell. The performance isn't fantastic but it's better than Nitrado, and the UI is garbage but at least it's not Serverblend. This is the one I would recommend today.

All of them are similarly priced with most server packages running around $15/month