Over & Over: Ahh I love this one. It makes dragging the vinyl out of all those
stupid inners worthwhile. It's sweet, melodic and oh so heart warming.
Think About Me: Is actually one of my least favourite on Tusk, I have to admit
I think it's probably the guitar (
) and the shared lead vocals. Admittedly, the lyrics are very very cute and there's a little AUU in there that makes me smile every time. John is on top form here, though, particularly on live performances.
Brown Eyes: 
Funny story, actually. RickRobert made a 10 minute loop of the sha-la-la-woah-oh-oh-ohh and I do listen to that quite often. The studio version, however, completely melts my heart. I adore it and it's my favourite song off Tusk.
Never Make Me Cry: Looks like I'm the only one with love for this one so far. It's one of the most memorable songs off the album for me. Chris' piano is just magical, IMO.
Honey Hi: Once again, so sweet. I think all of Chris' songs on Tusk are heartwarming but Honey Hi takes the biscuit. I think the lyrics are beautiful and touching considering all that She'd been through up to the point of the albums release.
Never Forget: I agree with Louie that this is a brilliant album closer. It's, shall I say, soothing, after all that just exploded through the speakers.