Running a Debian box, and wanting to find out what other packages you're missing out on ? Maybe you don't have enough installed already. I've got a mere 1246 packages installed on my main machine at home (only 518 on the secondary one), and I don't know where they all came from, though I'm prone to seeing lists of new packages and thinking "hey, I wonder what that one does ?". 6 months later I'll do a dpkg -l |grep ^i | wc -l and think "what the **** is all this ?", and spend 2 hours pruning anything I don't remember actually needing. But this is what free software's about ! Freedom to spend as much time as you want filling your disk with new and exciting software, only to remove it later when you can't remember why you thought it might've been useful.

So on the off-chance you don't have enough yet, Moshe Zadka's written apt-want, which will happily go and list all the (not-yet-installed) packages that are "Recommended" or "Suggested" (in Debian-speak) by stuff you've already got installed.