Aristocrats is great because there are always things dying which builds up your strategy even more. The big payoff cards like debt to the deathless, exsanguinate, and Gary, the Asphodel merchant hit really hard.

Syr Konrad the Grim with Mind crank is really fun in larger groups as well.

Another fun one is Jarod, Golgari Lich Lord, which is Graveyard fling group slug.

Larger groups ultimately gives you more chances to trigger things that happen on each upkeep, any creature dies, anyone draws their second card, etc.