I also thought of funnier contests :
->design a card that refers to victory cards in general (Tresaury, Rebuild, Trade Route, Silk Road, Jester, Haggler and so on) but not to specific victory cards (Tournament, Baron) to other type of cards along with "victory cards in general" (Fortune Teller/Vagrant that mention curses along with victory cards, and Ironworks/Tr-ansm/ib-ute)
->design a card that gains you gold mentioned explicitely (Governor, Transmute, but not Mine) that may happen on reaction (Marquet square/Tunnel/Fool's gold) but not on gain or trash (Sir Vander)
->design an action non-terminal trasher (lookout/spice merchant/upgrade)
->design a VP-chip gainer (and a good one)
->design a card that costs $5 and that may give you $3 easily without having to trash anything (contraband, harvest, cache, mandarin/count, but not tribute because it isn't that easy (okay, to discuss with harvest) nor explorer because it doesn't give you $3 directly, neither do beggar, and not merchant ship because I want $3 this turn, not the next one)