With the release of HoT each map in Central Kryta has its own individual Map Bonuses, mostly crafting materials and some other items and of course the relative Dry Top/Silverwastes rewards for those 2 maps.
These Rewards seem to be account-tied, as switching to another character in your account will not affect the ‘’Next Reward’’ of a map nor will exiting GW2.
Each Map has its own range of possible rewards and this range of rewards is the same for every player and every account
The higher the map level, the higher the tier and rarity (Lodestones) of the crafting materials awarded from it.
Some maps also award loot related to their environment and creatures that spawn there. Southsun Cove can give Karka Shells and Kessex Hills can give Pristine Toxic Spore Samples.
The order of the rewards for a Map Bonus doesnt seem to be important. For example in Cursed Shores, the Destroyer Lodestone stands below the Elaborate Totem and Destroyer Core, but above the Pile of Incandescent Dust and Pile of Crystalline Dust. But we all know that currently the Lodestone has a higher price than all of the above Materials.
All accounts begin from the same reward-item for each map, ie. Vial of Powerful Blood for Malchor’s Leap. Note that any item can be awarded twice or more in a row.
The first explorable areas of each race (Queensdale, Caledon Forest, Metrica Province, Wayfarer Foothils and Plains of Ashford) and the WVW maps do not give any Map Bonuses.
Presumably these items are awarded upon the completion of an Event, but that didnt always seem to be the case. I did a few tests in Mount Maelstrom with 5 events.
Defeating 2 of the Hidden Garden Keepers did award me with a Map Bonus Reward (2x Powerful Venom Sacs). The Champion Golem inside the CoE area, a huge Champion fish and 3 veteran Kraits (event) did not give any award, although all 3 of them are counted as an event.
Now I noticed that some maps have some very interesting items within their possible rewards:
Shiny Bauble can be earned from various maps.
Unidentified Dye from Diessa Plateau
Box of Cooking Supplies from Gendaran Fields
Azurite Crystal from Harathi Hinterlands
Obsidian Shards & Onyx Lodestone from Fireheart Rise
Charged Lodestone from Straits of Devastation! kudos to Anet for that, lets hope they didnt decrease its overall drop rates with this patch tho.
The most surprising one is Giant Eye from Mount Maelstrom. Currently siting at 6 gold in the Trading Post (was 6,7 gold before i started writing this post~30 mins earlier). Now would be a good time to sell them, as the price will drop even more after new brave adventurers make their way on the top of… IN the core of the mountain in search for Giants and their… eyes.
And who knows, maybe Anet will award each player with a point in their Giant Slayer achievement track if they manage to find one’s eye.
Dont forget to add to your Watch List
Anyway, I checked the wiki to see all the events in that Map and there are only 2 Meta Events (Mega-Destroyer and capture CoE). Perhaps the ‘’deliberately fail the 2nd or 3d event of the chain to start from the 1st again’’ strategy will help players in farming some Giant Eyes or maybe some other Event in the Map that trigger very often. Haven’t tested any of them so far.
P.S. I will not bother attaching pictures of every map, as rewards are the same for every player and all one has to do is open his Map(M) to see them.
. I left NA due to the time zone differences and no ppl online during my playing hours, but now I need to find people to play with xD (along with my 2 friends who are also planning to transfer to EU). 
