On my Debian boxes I use evilwm as my window manager, because it gets out of my way in just the way I like. Hence, I don't use gnome-terminal or kterm or ETerm or what have you; xterm has worked perfectly fine.
Nevertheless, I frequently spawn a lot of terminals, and the 5MB that each xterm process eats up (not including the 3MB bash does) add up after I fill a few virtual desktops with terminals. Xterm is also quite slow: cat'ing a 15K line banner output takes ~4 seconds on my netbook.
Hence, I went looking for replacements. Rxvt takes ~2MB per instance and cats the same file in ~1.2 seconds. Mrxvt takes ~3MB and ~0.5 seconds. Rxvt-unicode takes the cake, though, at ~3 MB and ~0.3 seconds. The real kicker, though, is its "daemon" mode, in which only once process is spawned for all "client" terminals, saving a lot of RAM. (Just hope it doesn't crash!)
Here's my setup:
URxvt*scrollBar: false URxvt*reverseVideo: true