An updated post (now with an executive summary) can be found here: http://www.dansdeals.com/archives/15417-----------------------------------------------------------------------------------------------------
This is one of the most common questions out there, maybe this will settle it once and for all?
With so many Starpoint transfer options I'm sure I've missed a few good options, please post a comment if you see a good one or if Ive made any mistakes!
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Star Alliance:Using ANA miles-If there is availability on Continental or USAirways for your dates: Transfer enough points to ANA to have 60,000 miles per ticket for coach or 90,000 miles per ticket for business. If you redeem ANA miles to go to Israel on airlines besides for Continental or USAirways you will be hit with fuel surcharges.
20,000 Starpoints=25,000 ANA miles. Effectively 48,000 Starpoints in coach or 72,000 Starpoints in business.
Using USAirways miles-If there is Star Alliance availability besides for Continental and USAirways, transfer enough points to USAirways to have 80,000 miles per ticket for coach or 120,000 miles per ticket for business. USAirways never charges fuel surcharges, although they do have a modest $50 award ticketing fee offset by the fact that they waive the phone booking fee for Star Alliance tickets.
20,000 Starpoints=25,000 USAirways miles. Effectively 64,000 Starpoints in coach or 96,000 Starpoints in business.
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OneWorld:Using AA miles-If there is OneWorld
or El Al availability, transfer enough points to AA to have 80,000 miles per ticket (for coach via Europe during off-peak travel times) or 90,000 miles per ticket (for coach nonstop on El Al or via Europe during peak travel times) or 135,000 miles per ticket for business nonstop on El Al or via Europe). There are fuel surcharges if you want to travel on BA, but not for travel on partner airlines.
20,000 Starpoints=25,000 AA miles. Effectively 64,000 or 72,000 Starpoints in coach or 108,000 Starpoints in business.
Using BA miles-If there is OneWorld availability for your dates: Transfer enough points to BA to have 65,000 miles per ticket for coach or 130,000 miles per ticket for business. If you redeem BA miles to go to Israel on BA you will be hit with fuel surcharges, but you won't pay a fuel surcharge for travel on partner airlines.
20,000 Starpoints=25,000 BA miles. Effectively 52,000 Starpoints in coach or 104,000 Starpoints in business.
Using JAL miles-If there is BA availability, transfer enough points to JAL to have 40,000 miles per ticket (for coach between 10/15-05/15) or 60,000 miles per ticket (for coach between 05/16-10/14) or 80,000 miles per ticket for business). Fuel surcharges do apply.
-If there is OneWorld availability, transfer enough points to JAL to have 60,000 miles per ticket for coach or 90,000 miles per ticket for business. Fuel surcharges do apply.
20,000 Starpoints=25,000 JAL miles. Effectively 32,000 Starpoints for off-peak coach on BA, 48,000 Starpoints for other coach travel, 64,000 Starpoints for business on BA, or 72,000 Starpoints in business on other partner airlines.
Using LAN kilometers-If there is availability on Royal Jordanian, transfer enough points to LAN to have 112,000 kilometers per ticket for coach or 224,000 kilometers per ticket for business. LAN does not charge any fuel surcharges
20,000 Starpoints=50,000 LAN kilometers. Effectively 44,800 Starpoints in coach or 89,600 Starpoints in business.
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Skyteam:Using Alitalia miles-If there is Skyteam availability transfer enough points to Alitalia to have 50,000 miles per ticket to Alitalia for coach or 80,000 miles per ticket for business, plus expect to pay fuel surcharges.
20,000 Starpoints=25,000 Alitalia miles. Effectively 40,000 Starpoints in coach or 64,600 Starpoints in business.
Using Flying Blue miles-If there is a promo award available on Flying Blue for your dates and you're ready to work hard to get them to honor it and cut through red tape: Transfer enough points to Flying blue to have 25,000 miles per ticket for coach or 50,000 miles per ticket for business, plus expect to pay fuel surcharges.
20,000 Starpoints=25,000 Flying Blue miles. Effectively 20,000 Starpoints in coach or 40,000 Starpoints in business.
Using Delta miles-You can also transfer to Delta Skypesos to avoid fuel surcharges for travel originating in the US (Delta charges fuel surcharges for travel originating outside of the US), but their mileage rates are variable. Coach can be between 80,000 and 190,000 and business can be between 120,000 and 370,000.
20,000 Starpoints=25,000 Delta Skypesos. Effectively 64,000-152,000 Starpoints in coach or 96,000-296,000 Starpoints in business.