American Airlines have got a great offer on the go, earn up to 25 000 bonus AAdvantage miles on every round trip up to a maximum of four times.
Though it's advertised as each round trip, if you read the terms and conditions carefully, you'll actually notice you're awarded the bonus per one-way segment, so you can still take advantage of this offer this if you fly on open jaw or one way tickets.
You will need to register via here, and fly between the U.S., Canada or Mexico and Europe on First Class, Business Class or full-fare Economy Class fares* on American Airlines, US Airways, British Airways, Finnair, Iberia or OpenSkies. Your travel period must be between 12 May 2014 and 31 August 2014.
Be warned, you need to have your AAdvantage address registered somewhere in North America first! You can get by it by changing your country to the United States and apply the zip code 90210 which is Beverly Hills in California.
Here is the earnings table
Bonus Miles Earned For Each Round-Trip
First Class or Business Class— 25,000
Premium Economy Class — 10,000
Full-Fare Economy Class — 5,000
*Includes First Class and Business Class fares booked in F, A, P, J, R, D or I; Full-fare Economy Class fares booked in Y, B or H on American Airlines operated flights; Business Class fares booked in C, D or Z; Full-fare Economy Class fares in Y or B on US Airways operated flights; First Class or Club World (Business Class) fares booked in F, A, J, R, C, D or I; World Traveller Plus (Premium Economy) booked in W, E or T; Full-fare World Traveller (full-fare Economy) booked in Y, B or H on British Airways operated flights; Business Class fares booked in C, D, I or J; Full-fare Economy Class fares booked in Y, B or R on Finnair operated flights; Business Class fares booked in J, C, D, R or I; Full-fare Economy Class fares booked in Y on Iberia operated flights; Biz Bed (Business Class) fares booked in J, R, D, I; Prem Plus fares booked in W, E, T, Z, A; Full-fare Economy Class fares booked in Y, B or H on OpenSkies
And the Terms and Conditions:
AAdvantage bonus mile offer is valid on American Airlines, US Airways, British Airways, Finnair, Iberia and OpenSkies operated and/or marketed nonstop flights for round-trip travel between the U.S., Canada, Mexico and Europe, May 12, 2014, through August 31, 2014. Offer applies only to AAdvantage members who are U.S., Canada or Mexico residents and who purchase and fly on eligible published-fare tickets. Flights operated by other codeshare partners are not eligible for this promotion. Bonus miles will be awarded based on the booking class purchased and can only be earned for a maximum of four round-trips. Half the round-trip bonus will be posted after each eligible one way segment. Bonus miles do not count toward elite status qualification or AAdvantage Million Miler status. Registration prior to travel is required.