Recs.
Updated
Destiny is an online-only FPS with RPG and MMO elements. You play as a guardian, trying to save the human race from aliens.
Read GameSpot review
SpecsUpdate
Pros
Pro Massive environments that feel alive
The open-world environments in games usually have a lot of empty space, so you spend most of the time traveling without doing much else. Destiny 2 has large areas filled with enemies, world events, and activity in general, eliminating most of the downtime. Because of this it feels like you're actually visiting a planet inhabited/occupied by aliens, which considerably adds to the immersion.
Pro Excellent co-op multiplayer
Even though Destiny 2 doesn't have strict class archetypes like most MMOs, each class/subclass has its role in a group setup. So whether you're capturing control points in a PVP match or fighting a tough boss in a raid, you still need to cover for each other's weaknesses. This can be providing support to surrounded teammates, taking the attention of groups of aliens or just picking off troublesome enemies from afar. Because of this you learn to rely on each other and working together feels rewarding.
Pro Solid controls that don't detract from gameplay
Your character's movement, aiming your gun, and even driving your hoverbike feels really fluid and responsive. As a result, you can make very precise movements, jumps, and shots in any situation, allowing you to land a headshot with your sniper rifle from far away while strafing with ease.
Cons
Con Content that was available at the start of the game ended up locked behind DLC
When the expansion Curse of Osiris was released, Bungie ended up preventing players without the expansion from being able to access the prestige versions of the first raid and nightfall strikes, as well as the PvP Iron Banner and Trials of the Nine. For the people who like to hunt achievements/trophies, this move effectively blocked them from earning them. Bungie has since patched things so players are not locked out of the prestige mode of the first raid, as well as nightfall strikes and Trials of the Nine when not using Curse of Osiris maps, making the achievements earnable again. Still, it was an extremely poor decision to lock player out of content they paid for and leaves the question as to will Bungie make another mistake with the next expansion.