Action Junkies - Borderlands 2 is one high-intensity combat sequence after another. Toss in the excellent, spot-on controls and button-mapping and the improved inventory interface and you've got a game that no Action Junkie should pass on, period.
Collaborators - This game is definitely better when played with friends. Gearbox clearly made Borderlands 2 to appeal to collaborators--they've provided incentives for friends or even strangers to play the game together. The game increases the difficulty level, gives you more money and drops better loot in proportion to the amount of people you have in your squad. On top of that, Borderlands 2 cooperative play is completely seamless. No ridiculous pre-game menus to sift thru. Just find a game, jump in and all your progress comes with you. This edition even gives you the option to skip over portions of your single-player game that you've completed with friends their games.
Explorers - Many people refer to the Borderlands games as "open-world" or "sandbox" titles. While this assessment is not incorrect, I do want to make a point to you more enthusiastic explorers out there. The world in Borderlands 2 is not completely open. It's a collection of decent-sized maps tied together by travel-hub loading screens and navigated by a stationary fast-travel system.
So don't think Elder Scrolls openess where you have the freedom to basically walk to anything you can see or immediately fast-travel to any location you've already visited. Don't let this discourage you, though. The real feeling of exploration comes from how the game allows you to approach enemy locations and combat situations with a large degree of freedom. Bottom line--Exploration is Borderlands 2 is open enough for most explorers to at least be satisfied if not blown away.
Audiophiles - I believe Borderlands 2 should be seen as the standard for how to execute a dynamic soundtrack. Not only is the music itself amazing, but the way it adjusts to what you are doing in the game is absolutely on point. The music, voice acting and sound effects all had a direct positive impact on my game experience. Extreme Audiophiles that need a dope soundtrack to pull them into their games should not be disappointed here.
I'd like to note that the voice acting is also handled dynamically. When I would encounter a battle with enemies around the same level as me, they would taunt me and talk a lotta smack. When I would either beat them down or encounter enemies much weaker than me, they would whine about me leaving them alone or at least ask that I don't loot their equipment once I killed them. Very well done.
Builders - The builder or customization elements of Borderlands 2 were what initially hooked me. However, by the time I started my 2nd playthru on true vault hunter mode, I was a bit burnt out because of the slow leveling progression. This game starts out significantly more difficult than the original (at least that was my experience playing as the Assassin). This makes it all the more sweet when you level up, enter skill points and return to an area where you got your ass handed to you to whoop some ass of your own.
With that said, if you are like me and plan to put in many hours of play beyond simply beating the game, be aware that the repetitive nature of Borderands 2 might begin to wear on you. Also, leveling from 40-50 seemed like an absolute chore--especially considering the sweet level-50 loot I'd been holding and could not use. EXP gets way too scarce too early in my opinion.
Achievers - For you completionists and achievement junkies out there, Borderlands 2 offers quite a bit to do. And aside from a few tedious achievements, most of it is a whole lot of fun.