From FlyerGuide Wiki

MVP (Most Valuable Passenger): For members who fly 20,000 miles on Alaska Airlines and/or Horizon Air; or fly 25,000 miles or 30 flight segments on Alaska Airlines/Horizon Air, American Airlines, Delta Airlines, LanChile and/or Northwest Airlines during a calendar year. Benefits include:

• 50% mileage bonus on Alaska Airlines/Horizon Air, American Airlines, Delta Airlines, LanChile, Northwest Airlines and Hawaiian Airlines flights.
• Unlimited first class upgrades on Alaska Airlines(restrictions apply).
• Preferred seating and priority boarding on Alaska Airlines/Horizon Air and Northwest Airlines.
• Dedicated toll-free Mileage Plan phone number.
• Priority standby for Alaska Airlines and Horizon Air.
• Dedicated MVP reservations line for Alaska Airlines.
• Two roundtrip complimentary first class upgrades on Northwest Airlines.
• First Class check-in privileges at Alaska Airlines ticket counters.
• 50% off Boardroom initiation fee.

MVP Gold: For members who fly 40,000 miles on Alaska Airlines and/or Horizon Air; or fly 50,000 miles or 60 flight segments on Alaska Airlines, American Airlines, Horizon Air, LanChile and/or Northwest Airlines during a calendar year. Benefits include the above listed, plus:

• 100% mileage bonus on Alaska Airlines, Horizon Air, American Airlines, Delta Airlines, LanChile, Northwest Airlines, and Hawaiian Airlines flights.
• Unlimited first class upgrades for Gold member and 1 travelling companion.
• 4 One Way Guest upgrades (fully transferable)
• Waived initiation fee to Board Room airport club.
• 50,000-mile bonus upon earning 75,000 actual flight miles in one calendar year on Alaska Airlines, American Airlines, Horizon Air, KLM, LanChile or Northwest Airlines.
• Four roundtrip complimentary first class upgrades on Northwest Airlines (only on domestic flights or on domestic portion of international flights).
• Express security line at select airports.