That totally depends on who you're playing for and what you're playing. For example, if you're playing Knockin' on Heaven's Door (the GnR version) to a big fan of 80s music, you may want to play the solos note for note. However, when you're playing for a bunch of teens (or just people that don't know the songs that well) you can do what my band does. We start a song, then totally improvise the solos. A good idea would be to mix the two.

One good reason to learn full solos is that if it's a famous song and many listener's find the solo great, then there must be something good about it. You may find some parts "boring", but but the listeners like it. Maybe repeating a lick four times, or doing a pentatonic roll is lame to you, but you have to think about pleasing the listener. If you get a case of "Guitarist's Block" where you can't think of anything to improvise, you can always fall back on the original solo.

Try doing the first few opening phrases to a solo, and improvised part, and the last couple phrases. It helps establish the song in the listener's mind, while still allowing you to throw in your own twist.

For guitar videos, take a look at Eric Johnson's Second video (Eric Johnson: The Fine Art of Gutiar 2, I think). It's in a white box with two video cassettes, if that helps. It's not all that advanced or complicated, but it really helped me think differently about chords and arpeggios. Rather than doing a 6-string sweep, it sometimes sounds better to do a three-note wide-spread arpeggio.