This thread in the Arch forums introduced me to some new lightweight applications.
In particular, I find epdfview and Mirage helpful, since they can easily replace the Gimp and Acrobat Reader for my purposes.
Geany is mentioned, although I don’t think it will take the place of Leafpad for me, since it’s more for coders than just editing text files. It has a lot of features that would just get in the way for me.
I like that urxvt (actually rxvt) is mentioned, along with Graveman; I use those already.
PCManFM is in the list, but it has fallen out of favor with me lately, because of the need for FAM or gamin to be running as a daemon in order for it to function. I’m not real keen on that, particularly when Xfe does the job just as well, and doesn’t need prodding.
P.S.: I feel obligated to include this page, although most of the applications it suggests are a little too lightweight for my tastes. 😉
Motho ke motho ka botho 
I used to use Leafpad but it’s search and replace was very inconsistent. Have you had any issues with that?
Yes! I have! And I’m glad you mentioned it because I had assumed it was something I misconfigured. I get mis-replacements when I agree to change out a string. Something like “abc” replaced to “def” gives me “abcdef” on the first instance. Is that what you get?
Yes, that is exactly what I get and is the only reason I stopped using it. I currently don’t even use a slim gui editor. I just use nano/vim for editing config files, geany for python, and gedit as the default gui editor.