I'd probably go for slots if you want something seasonal. The themes and stuff about it always change though the core of the game would always stay the same, so I don't really think it's suitable to judge it based on what season to play? Same with dice, though dice on the other hand can't really change its theme since well, it's dice. If I were to pick on what game to play though I'd go for Dice, it's pretty much something that you can play anytime anywhere after all.
Aside from promos and bonuses there is not a lot of seasonal stuff you can add to a game like dice so if we are only talking about those two games then I think that it is obvious that slots should take the vote of most of those which like to gamble.Even if the mechanics of the game of slots remain practically the same, the graphics can be easily adjusted to more closely reflect whatever season we find ourselves to be in at the time.
