Project M and its community is incredibly important to the internet and gaming as a whole. It proves that no matter what hurdles a company throws you, dedicated fans and talented people will always overcome them. Following the depressing closure of Project M due to fear of a C&D from Nintendo, from the ashes rises Project +. It's everything you loved about Project M except with a plus. More stages, more gameplay tweaks and of course: Knuckles the Echidna. Installing Project+ isn't as complicated as one might think, so I definitely think it's worth a play

As much as I love brawl as a game and as a collection of Sakurai-ian skinner boxes, even I have to take my nostalgia goggles off sometimes and admit that its a deeply flawed competitive fighter. For most of my time playing it, this didn't really matter to me because I didn't play it competitively, but after playing melee and the slightly more balanced sequels, it became clear that these more blatant flaws at very high level play were still manifesting themselves in the more casual modes. Project+ (and its predecessor PM) is an incredible solution to that problem, combining all of the best mechanics of smash to create a much better foundation for enjoying the incredible brawl content. It's one of the best mods for any game I've seen and is the definitive way to experience smash for my money.

Probably the greatest mod ever created; improves Brawl in every conceivable way by adding 100+ new stages, changing the system mechanics/balance, creating new moves and character animations & Knuckles. P+ isn't just a port of melee's mechanics onto Brawl's engine, it's clearly it's own game with thousands of hours of collective work and more passion behind it than a certain billion-dollar corporation will ever have (you can even play Brawl's single-player modes and more if you're into that).