Tanganyikans, if you're interested in something from the rift lakes. Shelldwellers like Lamprologus ocellatus, L. stappersi, L. similis or L. multifasciatus. Even the small Altolamprologus compressiceps "Sumbu" make intereting shelldwellers in smaller tanks. Rockdwellers like Neolamprologus caudopunctatus or N. leloupi and Julidochromis dickfeldi, J. ornatus, J. transcriptus or dwarf variants of J. marlieri (J. marlieri "gombe").
Or a pair of the beautiful fairy types like Neolamprologus brichardi, N. pulcher "daffodil", N. gracilis, N. marunguensis, or N. splendens (aka N. helianthus).
Overlook Malawian or Victorian cichlids. Most of them get too large/aggressive for a 29gl.
For non rift lake cichlids there are kribs - not just P. pulcher but P. tainiatus as well. If fact there are quite a number of Pelvivachromis sp. but some can be hard to find or challenging to keep.
Anomalochromis thomasi, the "African butterfly". A dwarf with a little attitude.
If you'd like something more like a Malawian fish but perfectly suitable to the smaller tank I would recommend a nice group of Pseudocrenilabrus. P. nicholsi seems to be the most available, not that it makes them very easy to find. Like most Malawian haps, males are gorgeously colored while females are a duller silver-grey. A male with a bevy of females will keep you entertained and will reward you with lots of fry.