Infinite XP and Gold Glitch
Before finishing a side quest that doesn't trigger a cutscene, draw your weapon. Once your weapon is drawn, talk to the NPC that completes the quest. Once your character puts his or her weapon away, repeatedly hit A till desired level or gold amount is reached.

Achievements
Master Craftsman (25): Crafted all of the items from a single crafting tree.
Mogul (25): Had 100 or more sovereigns in your purse.
Crowning Glory (25): Became the viscount of Kirkwall.
Dedicated (15): Reached Level 10.
A Friend in Need (5): Upgraded the armor of one of your party members.
Enchanter (5): Enchanted an item.
Immigrant (5): Became a resident of Kirkwall.
Delver of the Deep (10): Explored the Deep Roads.
Birthright (15): Kicked the slavers out of your ancestral mansion.
Specialized (25): Learned two class specializations.
I Got Your Back (25): Completely upgraded the armor of one of your party members.
Legendary (50): Reached Level 20.
Financier (10): Became a partner in a Deep Roads expedition.
Talented (5): Upgraded a spell or talent.
Tag Team (5): Used teamwork to perform a cross-class combo.
That Thing Has Legs (25): Found and killed a varterral.
Weapon Master (25): Mastered a weapon style.
Unstoppable (50): Completed a full year in Kirkwall without any party member being knocked unconscious.
Craftsman (5): Acquired your first crafting recipe.
Dragon Slayer (25): Found and killed a high dragon.
Exorcist (25): Found and killed the undying Xebenkeck.
Demon Slayer (25): Found and killed the ancient demon, Hybris.
Chantry Historian (25): Found all four chapters of "The History of the Chantry," by Brother Genitivi.
A Worthy Rival (25): Earned the Arishok's respect.
Great Minds Think Alike (50): Earned the friendship or rivalry of four party members.
Friend (25): Earned the friendship of one of your party members.
Rival (25): Earned the rivalry of one of your party members.
Romantic (25): Completed a romance with one of your party members.
Epic (50): Completed Dragon Age II twice, or completed it once with a save imported from Dragon Age Origins.(3)
Champion of Kirkwall (20): Completed Dragon Age II.
Mercenary (10): Allied yourself with the mercenaries upon arriving in Kirkwall.
Nefarious (10): Allied yourself with the smugglers upon arriving in Kirkwall.
Flirtatious (5): Flirted with one of your party members to begin a romance.
Mass Exodus (25): Reached Kirkwall with each character class across multiple playthroughs.
Knowledgeable (25): Unlocked 100 codex entries.
Treasure Hunter (25): Opened 50 chests.
Darkness Falls (5): Toggled the map from day to night.
Explorer (5): Left Kirkwall to explore the outlying regions.
Spelunker (25): Visited 10 caves in Kirkwall and the surrounding area.
Full House (10): Recruited four party members.
Friends in High Places (15): Met Grand Cleric Elthina, Viscount Dumar, Knight-Commander Meredith, and First Enchanter Orsino.
Gift Giver (5): Gave a gift to one of your party members.
Supplier (25): Found every variety of crafting resources.
Archeologist (50): During each year in Kirkwall, discovered 3 secret messages from the Band of Three.(1)
Tale Within a Tale (5): Listened to Varric begin his tale of the Champion of Kirkwall.

Dragon Age II: The Exiled Prince Achievements
Avenged (25): Confront the culprit behind the Vael family's murder.
Cloak and Dagger (25): Meet secretly with the agent of the Divine
Loyalty of the Prince (30): Earn either a friendship or rivalry with Sebastian.
Memento (25): Give Sebastian a family heirloom.
Retribution (25): Dealt with the mercenaries that killed the Vael family.

Legacy DLC Achievements
Conductor (30): Defeat an ancient evil in the Vimmark Mountains.
Deep Roads Safari (15): Kill a genlock, genlock alpha, hurlock alpha, bronto, and deepstalker in the Vimmark Mountains.
Family Legacy (30): Apply three effects to Hawke's Key.
Family Outing (15): Complete the main quest in the Vimmark Mountains with Bethany or Carver in the party.
Tower Sweeper (30): Complete every side quest in the Vimmark Mountains prison tower.

Infinite Armor Points
The Characters that can do this are Hawke and Aveline and can be done at any point in the game. To do this, equip, then un-equip, and then re-equip a shield. Your Armor number/ percent continues to go up as do this. You can do it as many times as you want until you've maxed out.

Unlimited Ability Points
To activate this glitch it will require that you have access to the black emporium and have money available to purchase the potion "Makers Sigh" that resets all ability points, and attributes. Hawke comes preloaded with preset skills he is "supposed" to have. Meaning when you use a makers sigh and save, when you reload the game file these ability's will be filled. To take advantage of this follow these following steps. 1. Use makers sigh 2. Save your game. 3. Load your game 4. Check your ability points. You should have the amount that were taken away, plus the ability's that Hawke is "supposed" to have. For a rogue it will be around four - five points in the dual wield tree. 5. If you use another makers sigh, it will now add those ability's to the ability points available. I was effectively able to go from 20, to 45 within 5 minutes. You must save and reload each time you wish to do this again.

Activate sustainable abilities that are not meant to be able to be activated together (Example: Control and Might for warriors are not meant to be able to be activated at the same time) Activate one, and before it's done casting, activate the other. It should activate them both and you should get the affects of both. This works for all sustainable abilities that are not meant to be able to be activated simultaneously.