This idea came to me. How many of these do you remember? Did you ever use it? I remember using all of these at some point.
Update: I'll give till Sat night if no one gets it I'll reveal the answers. Good job so far to all who've attempted.
spoiler
I legitimately still use Winamp as my main music player when I'm playing local files. I've had the same skin on it for over 20 years. I'll be crushed if Windows ever breaks compatibility and I can't install it anymore.
Also I still have mIRC and on the rare instance I get on IRC, that's what I'm launching, but it is very infrequent these days. :P