Honestly it depends on your tastes, but I'll go over a few.
If you like delicate plants that won't get trampled and bromelids in a more vertical build. Then ranitomeya would be good.
Imitators are extremely bold and come in several colors. Variabilis highland and southern, vanzolini are all pretty bold
If you want a good mix between arboreal and terrestrial then leucomelas are a good choice. The pic below is a Leucs tank I'm growing out with a bunch of neo broms. These are very bold and do well in groups
Tinctorius are probably the most are diverse with the larger varieties reaching 3" svl. These are territorial and do best in pairs. They're also very active and will use the entire viv if you make use of the negative space with branches etc. Plants need to be sturdy and pretty tough due to the size.
Phyllobates Terribilis (& bicolor). These are THE dart frogs. Natives use these to hunt. I have to physically move these to do work in the tank. They're bulky and more traditionally frog like. Extremely aggressive feeders and capable of taking crickets/roach nymphs. The setup will be similar to tincs but these rarely climb unless really wide shelves are provided. A must have for a dart keeper
Auratus have really nice colors but can be shy. El cope, boca, costa rican are the more bold morphs. These are reccommended a lot, but I sold mine due to me not seeing them that often. Care is similar to tincs
Once you get some experience then you can move into the pumilio category. These are stunning animals and the most expensive. I've seen them go for thousands per frog. They can be tricky with froglets.
View attachment 1339620