I recieved the Bordlerands 2 collector's edition game and guide for christmas. I never played the first borderlands and wasnt quite sure what to expect. I must say i am in love with this game. I even shelled out the 29.99 for the season pass on the dlc. The 2k super sale which is going on right now allowed me to pick up the mechromancer dlc for 50% off. At 400 msp it is a steal. I have yet to play co-op as my first attempt was ill fated and i recieved a disk unreadable error because someone was using Gaige. It booted me from my own game. The achievements are creative and aren't incredibly out there like some games. Some are story driven others are rare random monster spawn. It is a good mix. I'm really far behind on the curve as i haven't completed 1 playthrough or started the dlc(the next one drops on the 15th). The SHiFt system and extra golden keys is really awesome, even though i am just hoarding them for when i get to some of the higher levels and really need an equipment boost to propel myself forward through the storyline.
I find myself sitting down to play and getting up off the couch thinking it has only been 5 minutes, only to look at a clock and find that is has been closer to 5 or more hours. I love games like this, the ones that engross you so far in that you forget about anything else. I haven't had that feeling since i sank about 300 hours into Skyrim(and i am still nowhere near done). Overall this is my favorite game purchase in quite sometime. If you haven't yet pick it up even if you didnt play the first. It is a good mix of shooter and rpg that just leaves you wanting more and more.