All other things being equal, you'll generally want to select a location with the best connectivity that is roughly geocentric to your user base. What is the server being used for? Is your user base grouped in a specific geographic area or are they spread out pretty equally?
It depends on your target end user location, if your business clients are mostly from Europe, UK or Europe location is good. If they are from US then go for US datacenter location for your server.
This is a copy paste question and which has been posted in other forums as well. See here hostingdiscussion.com/vps-dedicated-colocation-hosting/68985-dedicated-server.html - I use few forums as a long term member and I have just found it there.
Server location plays a key role in terms of website performance. You can choose the server location based on the pointers below: Consider your target audience: If your target audience is from USA, you will need to pick a data center located nearby USA. Check for the datacenters offered: Since you have selected a dedicated server, you will get options for server location and choose the one which is closer to your audience. Check the datacenter’s performance: You can check the datacenter’s performance from several websites such as GTMetrix. It will give you an idea about if the web host is worth selecting or not.