Since I take interest not only in DOS games but also in other DOS software as well, I thought I'd be posting places on the net where such stuff can be found. Also, in no particular order:
Free Software for DOS A very nice and very comprehensive database of free downloadable DOS software, split into categories.
Interesting DOS Programs The site offers a selection of various DOS programmes, as well as links to other sites and various information.
Useful DOS Software A list of various DOS software by Joe Foster, author of The Star Commander, a DOS file shell that supports Commodore 64 file transfer and conversion.