I agree with everything MSPeconomist said.
Don't forget there are flights to AGP, VCL, BCN, and MAD on DL metal (at least this season, Spanish economy isn't doing so well.)
@:-)@:-) If you end up booking AF thru CDG, make sure you call to get the AF Record Locator, and don't let the uninformed DL agents tell you it's the same as the DL one. It's not. It will be very helpful checking in and if there are problems at CDG to have this number handy.
(nwa.com was very good at displaying any partner RL's, but delta.dumb doesn't)
Enjoy Spain, a wonderful country!