Certain game modes instead of rotating should stick around like ARAM does because of how loved they are!
Things like URF, One for All, and Black Market Brawlers should be an all year queue due to their success.
There are two modes I'd really like to see all the time.
They go by the names Team Builder and Solo Queue.
Dominion could be wonderful for offering an alternate League experience.
Unfortunately, Riot is so completely obsessed with SR that they'd somehow prefer the other modes atrophy and die off rather than support them. Since non-SR modes essentially have to survive without support, that only leaves modes which are competitive enough to have replayability, simple enough for complete beginners to understand, and varied enough (possibly through randomness) to not easily stagnate.
