I've always just used konsole or gnome terminal. Never really looked into what else is available. Tried cool-retro-term the other day, but the novelty wore off pretty fast for me.
Curious to see if there's a terminal someone swears by and refuses to use anything else.
Konsole and xterm, although I haven't had to use xterm in a while. Actually, circa 1997 I used kterm, the predecessor to konsole. ;)
Straight up Linux ttys are also quite common for me. Most old school distros still let you escape to the terminal, with CTRL-ALT-F1 or similar. I haven't distro hopped in a long time, so I don't know if other distros still do this.
I've always preferred Konsole because it handles several tabs pretty well and I keep a bunch open to my servers. The only issue I have with it is that it has a habit of detaching tabs if I click on one while my computer is running something heavy in the background.