How can I copy and transfer my Contacts List from Android to a PC?
How to Import Android Phone Contacts from Your Computer
Oron gives a good suggestion; I'd recommend just syncing them with Gmail and doing it that way.
Other than that, you could use a tool like AirDroid or SnapPea and export them easily through there.
It depends how you keep them on Android in the first place. If you use a GMail account and keep them in the default "People" app, they will be synced to GMail in the cloud by default.
Then, you can either export them from GMail (look it up in the GMail's help) for a one-time transfer, or you could sync them with the PC. I use Thunderbird and there are several addons avaialble for it, including gContacts, Google Contacts and Zindus (and probably others I haven't tried). For other email or contact programs you'll need a similar utility.
If you have a Samsung device you can download Samsung Kies from their website.
In the past I used SyncMate for such tasks but it looks like it is no longer developed for Windows (only Mac).