Pink Floyd's Wish You Were Here is pretty easy all around and fun to play. You get to do some picking out notes and some strumming. The one caveat is that there's an intro solo that, while easy, is supposed to be a second guitar.

Blackbird (the Beatles, not the alter bridge one)

All the 90's pop punk (Offspring, Blink) is very easy.

Neutral Milk Hotel's In The Aeroplane Over the Sea album is how I learned how to play guitar. It's basically all strumming chords.

What genre of music are you looking for?

Ace of Spades by Motorhead Paranoid by Black Sabbath

Polly and Molly's Lips by Nirvana are simple, and from what I remember, most Sex Pistols songs are quite straightforward too :)

Without a genre or tempo or style that's a pretty wide selection to choose from. Even taking an arbitrary limit like songs with 'big' in the title gets you a bunch of options: Big rock candy mountain, big iron, the big country, big river, big bang (bass), big shot, big train, big gun. Big love is a little more advanced, but big me is pretty simple. Look at the table of contents in a first 50 or first 100 songs to learn style book for more good choices.

I would mostly just be careful about classical/jazz/bluegrass/metal picks because of the long arpeggios or complex chord shapes. Pop, Rock, r&b, blues, folk are all usually safer picks for a quicker study.

If you're just playing the chords and singing the song, I'd say you can ignore any solos that are too difficult until you improve.

Nirvana and Red Hot Chilli Peppers songs can be pretty easy with not too hard lead parts.

I found that getting over that initial hump of difficulty was much easier with songs that I knew well, and that I could persevere with to get my skill level up.

Give us your top ten albums and I bet it would be easy to pick some songs

1979 by Smashing Pumpkins