I too always grab an aisle for the very same reason as lastlid. Also much easier to pop to the CR whenever.
If you can get a seat near an emergency exit there is extra-leg room, some airlines may charge a little extra.
The ones at the front of a block often get used for those with small children/babies as a cot can be used on the bulkhead wall. So yes there may be extra leg room, but there may also be some "baby disturbance".
We all have our own preferences for different reasons.
