Completed Super Metroid and my second Shin Megami Tensei IV playthrough (Chaos). Super Metroid is pretty cool and is one of the best SNES games I've played (via New Nintendo 3DS), though the final boss (Mother Brain) is really easy. I'd say the real final boss of that game was the 2 minute time limit in the game's escape sequence.
Regarding SMTIV, beat the game on the Chaos playthrough which was easy considering I was on New Game Plus. I also made it a point to fight the Demiurge and complete the Clipped Wings DLC, both of which were thankfully far more challenging than the main game. Once I return to that game, I'll do a Law playthrough and consider raising the difficulty level to prevent it from being too easy this time.