Get Super Punch Out!!
Starting today until August 4th on Club Nintendo, you'll be able to pick up Aura-Aura Climber (100 Coins), Star Fox 64 (200 Coins), Donkey Kong '94 (100 Coins), and Super Punch Out!! (150). While I can't wholly recommend Aura-Aura Climber, I think the other three are absolute classics that are definite "must plays" in their own way.
Super Punch Out!! in particular is my favorite in the franchise, and one I tend to speedrun every year -- in fact, I was serendipitously playing it last week. Donkey Kong '94 is also an easy recommendation, as it evolves the formula from the arcade classic in a huge way. Starfox 64 also needs no introduction, as it still holds up, and its branching paths are still engaging.
Although there are repeats in here, it's still a strong month.