If I have to both sing and play, these are the ones I can recite from memory, because it's hard to read my cheat sheets while sitting in front of a camp fire. I have enough trouble rememberizing lyrics as it is...
Acoustic guitar only.
John E.- Here's yer Beatles!
If I Needed Someone
Here Comes The Sun
Norwegian Wood
Mother Nature's Son

John Prine-
Please Don't Bury Me
Angel From Montgomery

The Byrds- (Sometimes I pack the 12-string)
Mr. Tambourine Man
Turn! Turn! Turn!
Eight Miles High

Bob Dylan-
You Ain't Goin' Nowhere
The Mighty Quinn

Neil Young-
Sugar Mountain
Needle And The Damage Done

Jonathan Edwards- Shanty (always a sing-along favorite)

There's a few more that have already been listed above. I have about an hour's worth of material I can play without repeating. Not to mention, the good old Blues stuff that encourages other players to join in.

Hurt - Johhny Cash

Patience - GNR

Good Riddance - Green Day

Wish You Were Here - Pink Floyd

Alice - Tom Waits

Yesterday - The Beatles

Jesus - Velvet Underground

Depeche Mode - Personal Jesus

Blackbird - the Beatles

Going To California - Led Zeppelin

Buckets Of Rain - Bob Dylan

Ambulance Blues - Neil Young

Where Did You Sleep Last Night? - Nirvana

Sweet Virginia - The Rolling Stones

Sunny Afternoon - The Kinks

Shape Of My Heart - Sting

so many good ones, try google too!

_________________
Being able to play and enjoy music is a gift that's often taken for granted.

Don't leave home without it!

Thank you, you are too kind. John.E