Without hesitation...4A.

Many of the E190s have 1x2 in the Stretch section, and if you have one of those aircraft you'll have a wide single seat to yourself. Legroom is about as good as exit row, though not spectacular. If you happen to have one of the E190 with 2x2 through the entire cabin, your Stretch seat will have much more leg room than exit row. The Stretch section on those aircraft have very abundent legroom.

4A is my favorite seat on the E190.