It really depends on what style of music or what type of band I'm playing with. If it's with a pop rock band (BREAKERBOX.tv) I will shoot for a more theme developed solo and if it's my own project (joepinnavaia.com) then I do whatever over-the-top thing I can pull of - Mainly for my own enjoyment. I'm really not very good at sweep picking but I have my own way of playing arpeggios.
I still feel that singing over a track to build a melody is best for a memorable line or solo. It helps with your melodic development as well.