>>23169615BW2's true way it shined was the challenge mode and the postgame. Not only do you have things introduced in the main game like Pokéstar Studios, you have a more challenging main game and when it's over, you still have bonus battles, Black Tower/White Treehollow, and the PWT which was nostalgic as all hell.
Gen V also introduced random ranked battles for the first time, which was the reason I decided to git gud at the metagame.
Oh, and the music in Gen V has some really standout tracks. Might not be my #1 region but when it has a good song it's a really good song.
Overall, Gen V made some experiments, some failed, some worked off great, I think the net sum is really good; it's a shame Game Freak ignored everything that worked great when they made Gen VI. I miss Gen V and hope Gen VII incorporates some of the things that made Gen V overall so good, though I know Game Freak isn't going to do that because it's not like they do that for any of the things that made other Gens good.