The title of my review really says it all for me, but I'll explain that a bit later.  For now, let's look at Pokémon Stadium 2

Pokémon Stadium 2 is only half a Pokémon game.  It removes all the questing and capturing portions of the handheld predecessors, and instead leaves you with a more tactically based gaming challenge.  No level grinding, no spending six hours trying to find one rare/shiny Mon, and absolutely next to no freedom in your customization of a team (Unless you have the pre packaged transfer pack).  Instead, you need to analyze the attribute points and attacks of the "rental" Pokémon, which are regular Pokémon with varying stats and abilities that you have no influence over.  This rental system (Unless, once again, you had your own team from a transfer pack) forced people to use a bit more strategy in choosing their moons from the start.  "I know this trainer has grass types, but what fire type should I use?  Ubers have awesome stats, but lousy skills; Final forms have decent stats but moves that are weak/have low PP; and the first forms are significantly weaker, but have great moves." People would spend time in careful consideration over what to choose, making having 2 player or 4 player matches extremely painful for the people not choosing their moons. 

The game has the story of every other Pokémon game ever made.  Assemble your team and take on the gym leaders/Elite 4 to become champion.  However, the kinda-story takes a backseat to the cups, which placed level and form restrictions to further challenge the players.  these cups include a petite, normal, elite, and prime cup  (Lev 15, 25, 50, 100 respectively).  Each had ten trainers, which got progressively smarter as the trainers went on, to a point where the 7th and upwards trainers were using their computerized brains to read and counter your moves.  This gets annoying to the point where they will sleep lock you (Using sleep powder immediately after you wake up).

All in all, it's a great game.  It's what got me into the N64, and it's what made me the gamer I am today.  Totally worth a buy for anyone.