As others have suggested, you first need to decide what type of setup you want. African lake cichlid are so different in their requirements and potentially so aggressive that they cannot be kept with ordinary community fish, and usually not even with fish from another lake than their own. So (if the tank is big enough), you have to decide if you are going Malawi, Tanganyika or community. And even community is best divided into either lively or peaceful, as timid peaceful fish can easily die from stress if put in with very robust companions.
African lake cichlids need quite a bit of room, they are aggressive and need to have space, and you do need quite good filtration. So not really something for a 25 gallon tank. The one exception is the one that has already been mentioned: shelldwellers. Something like neolamprologus multifasciatus. Shelldwellers are not as colourful as yellow labs, but they are very interesting fish, masses of character. They need a setup with hard, alkaline water, sand and lots of shells to live in. So you won't be able to keep ordinary community fish in this tank.
An RTBS is a lively territorial fish that grows quite big (up to 6 inches), so he wouldn't really be happy in a 25 gallon for long (and more to the point, the other fish wouldn't be happy.
Mollies and neons have totally different water requirements- mollies need hard alkaline water, preferably with a touch of salt in it, whereas neons need soft and acid and absolutely no salt. What I would do, would be to test the tap water and then decide between these two.
The angel is going to be a bit pushed for space, too. I would go along with the suggestion of a gourami instead- if you want a dignified fish moving peacefully through the water. Not a chocolate one, though, they have a reputation for being extremely sensitive. But you could fit in a trio of honey gouramis (1 male, 2 females) or a single pearl (aka lace) gourami. Gouramis don't mind being kept singly, but you should avoid getting two males, as they are territorial.
With gouramis as with angelfish, you need to make sure that their companions are not fin-nippers. So avoid serpae tetras, lemon tetras and tiger barbs. You should be ok with most tetras, livebearers (platies, endlers) and with bottomdwellers such as corydoras, khuulie loaches and bristlenose plecs. Of these three last-mentioned, the khuulies and corys are schooling- you want at least 3- while the bristlie can live on its own and your tank has only got room for one bristlie (they are heavy waste producers).
I would not put a betta in with either a gourami (they might fight) or an potentially fin-nipping fish
A suggested setup might be a trio of livebearers- I would suggest platies instead of mollies (1 male, 2 females or females only- but if you have both sexes, the females need to outnumber the males by a ratio of at least 2:1), 6 danios or black widow tetras (schooling species, so you want at least 6, not fussy about water), and for the bottom a trio of bronze or pepper corydoras.
Or: trio of honey gouramis, school of 10 neons, 4-5 khuulie loaches or one bristlenose plec
Or: 6 harlequin rasboras, 3 cherry barbs (1 m, 2 f) and 3-4 corys