Fire-type Pokemon got the short end of the stick this time in D&P, again, and didn't get much support in previous generations either. So obviously, with such a small cast, most of them should be acknowledged, but I do favour two sets above the others.
Torchic/Combusken/Blaziken are standard favourites for being simply commercial, but also because Blaziken is just extremely cool and worship-able. It was also the first incorporation of Fire and Fighting-type Pokemon right? Regardless, it made the way for Sweepers in all forms of battle and contests. :)
My second favourite is Ho-oh, simply because my first handheld Pokemon game was Gold, and I found that Ho-oh, despite having one of the worst type combinations in the game, as well as being a mere clone of Moltres, which I used to hold in high regard, is very smexy, appearance wise and in power. Okay, well, I admit that it's not that strong, but it's so pretty, and you gotta love pretty Pokemon. Rainbow wings and trails of golden dust makes Ho-oh equal win.