Full list of all 45 Need for Speed achievements worth 2,200 gamerscore. It takes around 20-25 hours to unlock all of the achievements in the base game.
The base game contains 30 achievements worth 1,000 Gamerscore, and there are 5 DLC packs containing 15 achievements worth 1,200 Gamerscore.
Completed 15 daily challenges
You tuned a car to max drift or grip settings
You've become the Ultimate Icon
You equipped top end performance parts to all categories on a car
You've reached REP Level 50
You've become an Outlaw Icon
You've uncovered the truth about the Outlaw
You've reached the top with your crew
You've become a Style Icon
You've become a Build Icon
You've met the legendary builder Nakai-San
You have beaten the Outlaw's "2 roadblocks in a pursuit" challenge
You maxed out all 5 scoring styles in a single moment
You've won an event with a tuned car
You've become a Speed Icon
You filled all the spots in your garage
You've beaten Magnus' personal challenge
You got called out by other racers 50 times for your skills
You've climbed aboard the drift train!
You've completed a single-take of Ken's Gymkhana
You've reached REP Level 25
You've beaten Magnus' record time
You competed against Amy's high horsepower contacts
You've learned to drive with style
You've found yourself a crew
You purchased another car for your garage
You've reached REP Level 10
You won three events in a row
Acquired your spot in the garage
You've taken your first snapshot
You won events driving Ken's and Morohoshi's cars
You put Ken's or Morohoshi's car in your garage
Get a 350000 Drift Score in Mental Block with Ken's car
You won an event in Eddie's Car
You completed Eddie's Challenge
Reach REP Level 70
You Reached Monthly Rank 10 by Completing Daily Challenges
You Shared a Wrap with the Need for Speed™ Community
You've Taken a Snapshot with a Filter in Snapshot Pro Mode
You won five Drag Race events
You bought your first Hot Rod
You downloaded a shared wrap
Win all the Prestige events
Win Gold on all Prestige events
Win all the events in a Speedlist