I'd like to start a thread to list out budget airlines which will help you to cross-the-pond cheaply without any other tricking etc.

Please suggest more and I'll update the OP (or make a wiki if I have access to).

Crossing Atlantic

Wow Airlines:
From: Boston (BOS) and Baltimore (BWI)
To: Iceland (KEF) as hub
Connections from hub: London and Copenhagen for now.
Typical one-way price in 2014/2015: $150, true budget option

Aer Lingus

From: Several US cities. Good network
To: Dublin as hub, connect all through Europe
Typical one-way price in 2014/2015 to cross the pond: Under $300 in winters, $500 in summers


Condor Airlines
From: Several US cities, including west coast. Good network.
To: Frankfurt Germany
Typical one-way price in 2014/2015 to cross the pond: $500 or so.



Crossing Pacific


.... not sure?