I tried Counter-Strike for the first time when I was about 10. Long time ago now. If I recall correctly it was temporarily free on the platform Steam. Must have been some kind of stragedy to make Steam more known... and it worked. See now, every gamer know what Steam is. So, not bad decision there. Anyways, my favorite map is de_dust2, de_nuke and de_inferno. I play these map when I play mixes (usually 5 players versus 5) where we use Ventrilo to communicate instantly with eachother.
And that's a screenshot of the 3 favorite maps of mine. A good song to listen to when playing CS casually is Spor - Aztec! It's pure win!