I recently scored a round trip LAX to Athens for 388 on Air Canada and I am trying to figure out how to maximize my miles. It is a tango fare so I know that is not as good for miles. I am new to the hobby. I am silver with Delta and have primarily flown with them the last 5 years. With the devaluation of miles I am looking to branch out. I am wondering which FF program within Star Alliance I should join to get the most bang for my buck from my upcoming Athens trip?

(1) What is your home airport? LAX
(2) What types of fares do you usually buy ? Discount Economy
(3) How many miles do you usually fly each year? 25-30k
(4) Do you have any kind of status at present? Silver Status on Delta
(5) What is most important to you in a FFP? Upgrades and free business class flights
(6) Which routes do you fly most often? LA to Portland 2-3 times a year. Mostly long trips to Europe, East Coast and Hawaii
(7) Preferred Airlines - Delta
(8) Do you travel for work or pleasure? Both