So, back in 1.23, we had some pretty nifty stuff. Like, Bravura doubled the duration of Vengeance, Gallant Gauntlets enhanced the potency of Holy Succor, etc. etc.
All of that is gone in ARR currently. I'd like to see it come back, so that gear selection doesn't simply just boil down to a raw numbers game. FFXI had all kinds of situational gear that was awesome, however that game also used gear-swapping in battle and I sincerely doubt many people (there are a few crazies out there) want to see that particular mechanic return. Instead, how about making the bonuses powerful enough to warrant using a specific item that might have lower stats than comparative gear full time? Another great option would be set bonuses for our new upcoming AF sets, but I'll get to that in a bit.
So, as an example, let's say DRG gets a new pair of i90 boots (just using current caps for the sake of argument) with similar stats to the current i90 stuff, as well as an i95 one that has more STR VIT etc. However, on these boots is an annotation reading "Enhances Jump Effects" Now suddenly every time you use Jump, Spineshatter Dive or Dragonfire Dive it's an automatic critical hit. Elusive Jump grants temporary invincibility (something it should do anyways but for the sake of argument I'm putting it here).
While it's not a straight up overall performance increase like the other pair, having a guaranteed critical hit with each jump skill can potentially game-changing. Another item could be "Enhances Fire-starter" for BLM raising the chance of proc to 60% or more etc. etc.
The other thing I'd like to see as I said before is set bonuses, particularly for our Job-specific AF sets; A powerful bonus only granted when wearing all 5 pieces (and possibly above the 10% dmg threshold. Definitely can't be broken anyway.)
For Paladin, it could be a passive -10~15% damage taken, or a critical hit chance (not rate, straight up % chance increase) for Bard. This is the kind of variety that is sorely lacking in endgame equipment and I get that we don't have it right away given the game hasn't been out long, but it needs to happen at some point.
It also doesn't have to be restricted to armor. It'd be nice to have added effects on weapons again, like how Ifrit weapons used to deal additional fire damage.