Destiny may not have the best story, and it can feel like a bit of a grind at times, but the vast amount of different experiences you can have in the game is really impressive. Crucible matches, collecting items, upgrading weapons and armor, exploring other game modes, and playing through expansions give you a huge wealth of things to do after you've finished the campaign.

Even if you've been playing Destiny since the day it came out, there are probably still a few things you haven't done. If the game is starting to feel a little stale, try one of these adventures to keep it fresh. And if we've missed any good ones, be sure to let us know in the comments!

Alternate Crucible Modes

The standard Crucible modes, like Clash, Control, and Rift, are a lot of fun -- but there are some other PvP modes you can take on for more challenge and variety. Once a month, for example, the Iron Banner Crucible mode is accessible; in this mode, player's Light levels aren't equalized, so if you have better gear, you'll do more damage. It makes for an interesting challenge, and the rewards you can get are pretty awesome.

The Trials of Osiris is another Crucible mode that comes along every week; it's an Elimination-style 3-on-3 match and, like Iron Banner, level advantages are enabled. Your participation is limited, too, once you hit three losses or nine wins, your current run ends. Again, you can get some really impressive rewards from this mode, so the competition is fierce. There's also no matchmaking, so you'll have to gather your own team of three to enter the Trials.

Hidden Quests

Even if you've finished off all of the main quests, there are still a number that are available to you if you know how to unlock them. Most of them unlock Exotic weapons and armor; you can get vaunted guns like the Sleeper Stimulant, The Chaperone, Imprecation, Boolean Gemini, and No Time to Explain (pictured below). You can also get Exotic Marks from your Faction-specific quest. This list from IGN contains Exotic Quests from the Taken King expansion to get you started.

(A quick note: all of the Exotic quests have been unlocked, so they're no longer tied to specific missions or days. Just select the appropriate mission from the map and choose the Heroic version.)

There are side quests that you can complete, too; things like forging an Exotic sword heavy weapon, earning your place in the Sparrow Racing League, and completing tasks here and there for Amanda Halliday all reward you with cool gear (and are fun to complete).

Prison of Elders

If you haven't checked out the Prison of the Elders since its release in House of Wolves, you're missing out on a lot of awesome play. It used to be pretty straightforward and easy to survive through five rounds, but with the addition of a level 41 option and the Challenge of the Elders, a punishing level 42 fight, it's really enjoyable.

The Challenge of Elders is especially great; each week, new modifiers are applied and bonus point categories are established. If you manage to score over 30,000 points in a single run, you'll be rewarded, and if you score a total of 90,000 cumulative points in the Challenge, you'll get more gear. It can be quite a challenge, so it's not for Destiny beginners. But the combination of great rewards and a test of your skills make this my personal favorite mode.

Find All the Ghosts

You've probably noticed the dead ghosts sitting around in dark corners of the maps, but did you know that there are over 100 of them to find? At the time of this writing, there are 103 ghosts to find across six different locations (the Tower, the Reef, Earth, the Moon, Venus, and Mars). There are also 50 Calcified Fragments hidden on the Dreadnaught for you to find.

While it's probably possible to find them all on your own, it would take a crazy amount of time and effort, so there are sites that will help you find them. Destiny Ghost Hunter (one of the best Destiny-related sites) is a good resource; it will show you which ones you've found, which are left, and how to get them. And Destiny Tracker has a good tool for finding Calcified Fragments.

Both ghosts and fragments add entries to the Grimoire, so you can learn more about the backstory of the Destiny universe. If you haven't spent any time reading the Grimoire, I recommend it; especially the entries unlocked by the Calcified Fragments. They all tell an interesting story, and give a lot of insight into what the plot of Destiny could have been.

Complete High-Level Missions

It's likely that you've gone on a raid by now, or gotten a group together for Nightfall missions; but if you haven't, it's a great way to extend the Destiny experience. Raids are really hard, and even the highest-level players might take several hours to complete one. Nightfall strikes can sometimes be even more difficult, and you'll want a high tolerance for starting over from your last checkpoint to successfully take one on.

That being said, this is where you'll get the best gear. Raid weapons and armor are very high-level, and Nightfall strikes drop extremely valuable loot when you complete them.

Collect Crucible Medals

You've probably noticed that you can earn medals in the Crucible for doing certain things; you get Machine Lord for three machine gun kills in a single life, for example, and Nail in the Coffin for scoring the final points in the match. But there are a lot of medals that you probably haven't earned yet, and they can be a lot of fun to go after.

The Gunner medal, for example, rewards you for getting five turret kills in a life, and the Zero Hour medal indicates that you won a match in overtime. You'll get the Hazard Pay medal by killing an opponent with an exploding object. My favorite medal is Never Speak of This Again, which you get by killing an opponent by running them over with your Sparrow.

The Medals & Weapons section of Destiny Tracker shows you how many times you've earned each medal and which ones you're missing.

Earn Trophies

In addition to Crucible medals, you can also get game-wide achievements for Xbox or the Playstation Network. Many of them will be unlocked in a regular playthrough of the game, but others will take more effort. Flawless Striker, for example, requires that you complete a Strike without anyone in your Fireteam dying. Strength of the Pack will be unlocked after you complete a strike with only members of your clan.

Epic Raider requires that you finish a raid on hard mode, which can be a serious undertaking. Flawless Raider, as you might guess, requires that you finish a raid without any deaths on your team, which is extremely difficult. Triple Play is a Crucible achievement that's unlocked after you kill a Hunter, a Titan, and a Warlock in a Crucible match without dying.

There are plenty more achievements you can go for . . . and if you unlock them all, you'll get a platinum trophy and be in elite company indeed.

Collect All the Gear

Of course, there's plenty of collecting to do. Getting all of the Exotic weapons and armor will take a long time, even if you get really good using Xur's Three of Coins. Getting all of the class-restricted items, faction-specific items, emblems, emotes, event gear, and Sparrows is a serious undertaking, and will take many hours, even if you look up online how to get them all. And with new gear coming out with every expansion, there will always be plenty more to find!

How Do You Keep Destiny Interesting?

Destiny is a huge, sprawling game that keeps millions of active players coming back, but once you finish the main objectives, you can be left looking for fun things to occupy your time. The tasks above should give you a lot more to go after. I've put in a few hundred hours at the time of this writing, and I still play pretty regularly. The adventures above help keep the game fun and make it a great investment.

How do you keep Destiny interesting? Are you a collector, or do you spend a lot of time in the Crucible? Have you found all of the Exotic items, or are you not really concerned about getting them all? How do you spend your time in the Destiny universe?