I just went ahead with some spring travel planning courtesy of the ever-useful Kayak and discovered some incredibly cheap Newark-Spain fares in April on TAP Portugal.
According to the airline's homepage, there are current promotional fares fares to Madrid, Seville, and Barcelona via Portugal for as little as $518. The multistop itinerary I researched between Newark to Barcelona on the outgoing leg and returning from Bilbao, via Lisbon in both directions, came in at a very attractive $541 roundtrip.
Also of note: Roundtrip fares to major Italian destinations (Rome, Venice, and Milan) begin at $556 and roundtrips to Lisbon and Porto begin at $619.
