Here is a nice one from AC/DC's Angus Young. This is from the solo to "You Shook Me All Night Long". This is a great example of the mixture of minor pentatonic and major pentatonic sounds. This lick is in the key of G, and can be used over any Bluesy G major situation. And of course this lick can be transposed to other keys as well.

Left hand fingers
     |
     2 1 1    2 1 1   2 1 3____  4   3____  1
E:------------------|------------10--------------
B:-----6-6------8-8-|---8-10b(12)---(12)r10-8----
G:--/7-------/9-----|-9--------------------------
D:------------------|----------------------------
A:------------------|----------------------------
E:------------------|----------------------------

    1 3_____   3_____  1 2 1
E:------------------------------
B:--8-11b(13)--10b(12)-8---8----
G:-----------------------9------
D:------------------------------
A:------------------------------
E:------------------------------

The red numbers are the notes that you should use as your guide. In this case the red note is a G. If you wanted to play this lick in the key of A, then you would move everything up 2 frets so that the notes in red would be at the 10th fret (A).

For more information on how to read this, check out the lesson on reading Internet tablature.

I am now going to break this lick down into 3 separate parts and show what scales are being used.

Part 1

The first 2 notes are coming out of a position of G minor pentatonic, and the next 2 notes come out of G major pentatonic.

Part 2

Part 3

Part 3 again uses a combination of G minor, and major pentatonic.

For more on pentatonic scales check out this lesson.

Minor pentatonic - it's the king daddy of all scales used for improvisation on the guitar.