I recently started this little gem, Therian Saga.
http://www.theriansaga.com/ or
referral link
It's not really a flash game, it's a crafting browser game (probably made with flash?). Now some of you may know of browser games, they manage to be pretty much the worse games ever because of how many microtransactions they have, this one is different.
The basic gameplay is a massive crafting game, you pick what your character specializes in, metal working, wood working, hunting, commerce, engineering and then you just explore the world and craft stuff. There's a total of 27 disciplines and you can master them all, with time. Say you want to craft a spear, you'll need to dig some ore, get some charcoal, purify the metal, then chop some wood, refine the wood into a handle, then craft everything into the spear. Items require different disciplines to make so that encourages trade and interactions with others. You can recruit NPCs to help with your skills or even tame monsters (that's what I specialize in). You can even craft whole towns eventually, and another late game are dungeons. Twink your character to the fullest, gulp some potions and then assault the dungeons, of course they offer rare rewards of their own.
What makes this game special is the gameplay is actually original, and it's extremely relaxed. The developers make money by having energy, you can buy potions to cut down on the time to do things of course, that's the P2W aspect of this game. But no one attacks you, you never lose anything for being a casual player, and it's not really the game you want to binge on. You can play the game for 20 minutes a day, just queue up actions until your energy runs out. Oh and you can buy the store currency on the auction house with your mad trading skills.
I know there's quite a few crafters out there on the Codex, it's a great one. I'm on the Wojtek server btw, Renegen. If we have enough codexers we could even form a guild, although believe me those things are most than just a group chat.