Doc - Pichu roulette: Have two Docs and two Pichus on FD. Put the Pichus in the middle of the stage and charge neutral B. The Docs can only cape, and they try to time it so the other Doc gets owned by a flying Pichu.
Fox shoot em' up: Pick stamina mode and all Fox. Go to either Poke' Floats or Icicle Mountain. All players can only jump and use lasers, no dodges or recoveries. Hilarious when you face someone else and spam standing laser, and realize you're either losing and need to jump away or you're behind someone and destroying their hp.
Jiggly RnR: Pick FD, 4 stocks and all Jigglypuffs. All players can only jump, rollout or rest. On FD, a puff can survive a rest at 0% so you need to get a rollout in first. Rollout kills and suicides (can't grab the ledge after hitting someone with rollout) are great, and everyone loves resting a group of Puffs that failed to rest another sleeping Puff.
1v1 Shine Bair contest: Both players pick Fox, 4 stocks, and FD. Whoever can get more shine bairs on the other player wins. You can do a round robin format with each shine bair adding to your total. Grime points include killing the other Fox after obtaining a shine bair. Alternately you can set a time limit instead of the stocks.
Infinite spacie dittoes: Two players either pick Fox or Falco, infinite time, any stage. Watch the hours fly by, and your hands crumble to dust.
Falcon Punch Points: Pick two teams with team attack on consisting of at least one Falcon on each team, but only one Falcon "counts". 4 stocks and any stage. Each Falcon punch the designated Falcon on each team landed on the opposing team is worth one point, or two points if the Falcon Punch kills. Each Falcon Punch landed on your teammate is minus one point, or minus two if it kills. The goal is to have more points than the other team AND win the game. The Falcons' teammates are to setup the Falcon punches by grabs, but be careful if they mash out since you might get hit instead!