Brief summary/thoughts: http://us.battle.net/d3/en/item/bane-of-the-powerful Increases your sheet DPS by 20%(additive). Requires you to kill Elite mobs AND their minions. 15% elite dam at 25 is decent http://us.battle.net/d3/en/item/bane-of-the-trapped Possibly the best gem in the game. The damage buff is multiplicative to ALL your damage. NOTE: Currently this gem is bugged in that procs like from SoH are NOT being amplified right now. http://us.battle.net/d3/en/item/enforcer Additive damage again. Is okay alternative for DH and WD. Pets taking less damage is just meh http://us.battle.net/d3/en/item/gem-of-efficacious-toxin Applys once and does not stack PSN. HOwever, the 10%, according to most, does scale per using in a group. Otherwise, not a gem of choice. Okay for kiting... http://us.battle.net/d3/en/item/gogok-of-swiftness CDR. When you need it this gem works wonderfully. Great for Monk or Sader http://us.battle.net/d3/en/item/invigorating-gemstone Perhaps the poorest choice in design, but I have seen people use it that just do not feeling like moving for damage. LOL May yet have application in very high GRs where jailer damage can actually kill you.. http://us.battle.net/d3/en/item/mirinae-teardrop-of-the-starweaver Random damage is random. Great for bosses and is improved by + holy%. Sader gem for the most part, but I have seen some monks toy with it. http://us.battle.net/d3/en/item/moratorium One day there will be something better defensively---but until then...you got this.. http://us.battle.net/d3/en/item/pain-enhancer Physical builds love this gem. Monk, Sader, Barb. IAS increase is a bit small given the range so being up close to your targets is better. Could also serve well for a pet build for WDs. http://us.battle.net/d3/en/item/simplicitys-strength Tanking gem. Unless you are bored and making a tanking monk I would say there are better choices http://us.battle.net/d3/en/item/taeguk Supposed to be for channeling builds. Unfortunately, you still cannot stand in stuff, even with the buff if you are ranged. Works well for staff monks with almost unlimited resources. Wizs, you have much better choices. http://us.battle.net/d3/en/item/wreath-of-lightning This was my first gem. Loved it. The range is short but it is amplified by + lightning %. Monk/Barb applications http://us.battle.net/d3/en/item/zeis-stone-of-vengeance If you are not a melee ranged class this gem is fairly awesome. The damage boost is multiplicative. Just like trapped. The stun proc is not great as a downfall. Given the scaling in game it is very easy to be 20 yards from your target or if you run a kiting build. Pretty hard to beat. Please feel free to add applications you have found and how well you think it works. Also, if you have any questions please ask.