Here's an old one from my modest demo collection between Matr0x and Zero4 (called 'ender' in this match) on cpm3. Unbelievable rails. This has to be one of the fastest matches I've ever seen and cpm3 teleporting seems pretty confusing in a hub aero sort of way.
the best way is to setup a recording script like this:
set rec "vstr first_rec"
set first_rec "g_synchronousclients 1;wait;record;wait;g_synchronousclients 0;set rec vstr second_rec"
set second_rec "stoprecord; set rec vstr first_rec"
bind x "vstr rec"
with 'x' being the key you want to turn recording on/off.
every time you start recording, it saves to a new file (demo001, demo002, etc..)
for playback, I believe its: /demo demoname (type in console)
save the script in your autoexec.cfg file in /baseq3 folder
if you dont know about autoexec then you'll have to research it.