TAP will be cheaper but they suck. I would choose Lufthansa.

whichever has better price / connections. Both are fine.

I agree with you! The connections are better, actually. Thanks!

Tough call, I prefer lufthansa and they have soooo many flight connections to Spain.

But, TAP is just so much closer geographically from the East Coast. I really hate having to fly to central Europe just to turn around to get to the Iberian Peninsula. So...I'd probably go for TAP unless they have given you a ridiculous connection time like 6 hours sit in the Lisbon airport between flights.

We can fly from Spain through Lisbon on TAP or through Frankfurt on Lufthansa. Which would you choose? Thank you!