Let's talk about the SAO event (even though I haven't even been in it).
So the way it works is you talk to the informant NPC in Fiodh and Peaca lobbies/just outside Math and Alby to get a pass to enter a Zone. At first you can only access zone 1 (easy and super short), but as more and more people from across the server do these dungeons, you'll eventually be able to go to 2 through 5. For reference, I think we're up to 2 and almost 3 right now.
When you clear a dungeon, you'll get a map piece for the specific dungeon and zone you just cleared (Alby 1, Math 3, etc). You can trade these in with the informant to get a general dungeon ticket (only has the zone number, can be traded). These are what you'll be further trading in with the sysadmin for Cool Rewards. There are also System Administrator Access Codes that can rarely drop from monsters that you can trade for
anything.
Rewards include various crystals (basically free potions that also are antidotes, apparently), the Divine Stone of Returning Soul (7x4 potion bag), and the especially cool 2nd title coupons. Here are the bonuses and costs, with (!)s noting how amazing some of these unique boosts look.
ALO Asuna - Taming Success Rate +20%, Magic ATT +40 (!!!) and Bolt Magic Damage +2% (amazing matk boost) 100 Zone 4 or 60 Zone 5
ALO Kirito - +7 max, +10 str, 2% speed (pretty standard) 100 Zone 4 or 60 Zone 5
SAO Heathcliff - +10 max, +5 defense, +5 protection (both offense and defense!) Only comes from sysadmin code
SAO Klein - +10 will, +15 luck (well that's like 4% crit..) 60 Zone 1 or 15 Zone 5
SAO Lisbeth - Refining Success Rate +2% (!), Blacksmithing Success Rate +3% (!!!!!), and Gathering Speed +5% (!) (BLACKSMITHS GET THIS NOW)
SAO Pina - Cures wounds as much as 5% of the Healing effect and increases the Healing effect by 15% (ghetto Party Healing Master) 100 Zone 3, 60 Zone 4, or 30 Zone 5
SAO Silica - +24 magic attack, +10 mp (almost as good as the old prefixes for magic attack) 60 Zone 2, 30 Zone 3, 30 Zone 4, or 20 Zone 5
Wow!! Those are all pretty nice, except Klein! Of particular note are Lisbeth, ALO Asuna, and Silica. Free smithing success rates are always welcome, ALO Asuna's magic attack boost rivals Scathach (a notably super awesome title from the last sale), and Silica is basically ALO Asuna but weak. I would strongly recommend
stockpiling multiples of all the titles to sell in a few months when the costs skyrocket. At least, that's what I'd do.
But wait, there's more. Each of the dungeons drops combo card fragments that you can stick together to make
ACTUALLY USEFUL COMBO CARDS. What a novel concept!!! You can just stick 5 Firebolts in one card or something. It's pretty great. This is also a reason to do other dungeons besides Alby all day every day, because they give different skills. See the wiki page to know exactly where you can get what you want.
At this point I don't even care it's a SAO crossover or anything. The rewards are just so nice.
e: I have been deceived, turns out you can only get the sweet Lisbeth smithing title from buying the outfit. Okay.