It's worth noting that when the contest rewards are unique people complain about how a contest is the only way to get certain items (double drop items come to mind) but then once they're available elsewhere all of a sudden contest rewards are "useless".
That particular item being contest (or sometimes purchase) only was a real hindrance to players that needed it the most.
Personally there's nothing on offer rewards-wise that I need. I just roll the rewards of one contest into the next appropriate one without paying too much attention but I worry that if we push the wrong items into contest rewards we hurt what this game needs so badly. Newer players.
Something useful but not critical would be great. Stam or diamonds are always good for pretty much anyone
Items that mirror events for 12hrs similar to the double xp items wouldn't change the world but would mix it up a bit. Things like double fight pit, double coli, double boss etc. A free rune removal item would be pretty exciting to a lot of folks.