Appetite's my favorite album of theirs in the sense of cohesion and flow, but UYI1 is my favorite compilation of songs on an album. Not a single bad track.
Live And Let Die (I wish they'd let this song die live)
You Ain't The First
Back Off Bitch (but I really don't wanna vote for this one)
Get your grimy hands off of Dead Horse and Don't Damn Me!
Edit: Just noticed Bad Apples and Bad Obsession have 6 votes each. What a shame. Bad Obsession is one of their best live songs, and Bad Apples has some of their best lyrics. I love the lyric, "I said your laundry could use washing, we'll hang it up all over town. I said Hollywood's like a dryer and we're down on Sunset Strip and you'll be suckin' down the Clorox 'til your life's all nice and crisp."
GN'R's never been the most lyrically compelling band, but Bad Apples, Don't Damn Me, Coma, Right Next Door To Hell, and Dead Horse are the exceptions (from this album).