I'd start with VICE. It's been pretty good for me. Free, runs on even Win 10, supports the most game image files, and it's pretty customizable for keyboard, mouse, joystick controls.
http://vice-emu.sourceforge.net/
And as a bonus, it not only emulates the C64, but also C128, PET, CBM II, VIC20, PLUS/4. So if you have any of those images you can play them all.
Also if you would like some more C64 games check out
this site. It's a horribly designed webpage, but it has almost all the C64 games ever made for download.
Or for them all listed under an alphabetical FTP site (much easier to use)
you can go here. But you're still downloading one at a time on that one.
EDIT the forums software for links keeps trying to put an "HTTP://" in front of that link. But it's an "FTP" link. So copy paste this into a browser to see this one.
ftp://arnold.c64.org/pub/games/
Of course if you'd like to just have a lot (around 10,000 titles) in one easy to grab file, then go to
this one. It has a zip file you can download, but if you have torrent software installed the torrent is a bit faster to grab.