"No Rain" by Blind Melon
"Far Behind" by Candlebox
"Cliffs of Dover" by Eric Johnson. I only have one cd of his, but I like almost everything on it now, and I want more. Now "Cliffs of Dover" and "Nothing Can Keep Me From You" are by far the two most played songs on my iTunes.
"Rubina" by Joe Satriani is probably the most recent example. I discovered it exactly how I discovered Eric Johnson. I was sitting in my room, and my dad was in the room next to me, loading music onto his computer. The guitar sounded familiar, and I liked it, so I went in and snatched it from him.
I know I am going to catch some flak from this one but...
"Over the Hills and Far Away" by Led Zeppelin. Yes, they are classic, yes they are one of the most influential rock bands of all time, and yes, there was a time when I just plain didn't like them. But when I heard this song, I immediately liked it, so it got me into exploring some of their other stuff, and now I like Zeppelin a lot more.