I like it to a certain extent; it's fast, straight to the point, and generally has all the information you'd want.
Sure, it's aesthetically lacking, but honestly, when I'm looking for ROMs, I don't really care; if you have it, I'll come. I think aesthetics can be something you work on later.
Considering this is a ROM site, hence mostly file downloads/uploads, I assume that you'll want to cut down on the bandwidth that isn't used by ROM downloads. Thus, cutting back on graphics is a good idea; perhaps, instead of long strings of "<br />" to display lists, you could use actual lists? UL and LI, thank you.
I don't have much more to add. The source is alright; except it's weird that your files are located in your home directory, and not the public_html (or so I assume, since you call them using "../file.php".
Anyway, good job on this; it's not my dream ROM site (which would be modeled after Google, except slightly modified for faster search), but it works.
As for ROMHacking, there is ONE site which covers it, and in darkness binds them: ROMHacking.net, home of the largest collection of documents, utilities, translations, etc etc. It's Nightcrawler's site, so...eh.
Good luck anyhow!