In 25E you have a bar almost directly behind you, but you have a little more privacy from aisle. If you'll want to sleep the bar may annoy you. You'll also have the joy of watching almost the entire cabin eat before you.

In 17B it'll be quieter but you are a little bit more on show as the mini bar etc is by the window.

I prefer to avoid the middle seats when travelling alone, but others may feel differently. I'd go for 17B.