My favourite is Every Little Thing.
I've always regarded it as a real buried gem of a Beatles song and I'd never heard anyone mention it much - until one day I read that it was the most played song on the gorgeous Lauren Laverne's ipod!
Remembering my vinyl copy, from side one I always loved No Reply, I'm A Loser and I'll Follow The Sun.
From side two it was Eight Days A Week, Every Little Thing and What You're Doing.
This being the era of the LP, when you couldn't just skip tracks with a remote control handset or pre-programming, I actually grew to slightly resent I Don't Want To Spoil The Party, annoyingly sandwiched in between my two overall favourites on the entire album. I wanted them back to back!
What You're Doing I always regarded as Paul's downbeat answer to "John's" more optimistic Every Little Thing. It was only relatively recently that I learned ELT is in fact apparently a Paul song, despite John taking the main vocal. Can't recall them ever doing that before (or since)?