"Scar" by missy higgins is pretty bouncy regardless of content
"Allegro Cantabile Sound" from Nodame Cantabile
"Hounds" and "Hotdog wolf" from Wolf's Rain - these have a sort of swing to them, particularly "hounds", that just work really well to lift a mood
"All Star" by Smashmouth
"Destined for" - I don't know who it's by but I have it listed under random anime on my ipod
"PRIDE" by HIGH and MIGHTY COLOUR
"Die another day" by madonna (shock!Horror! She produced something decent!)
"E Komo Mai" from Lilo and Stitch is good for feel-good factor
If you don't mind the occasional rap verses maybe "CHANCE!" by UVERworld, again feel-good factor
"Open Your Heart" and the Reprise version from .Hack
"Slide" and "Iris" by the Goo Goo Dolls
"Electric de chocobo" from ffvii is good for just plain quirkiness, despite being a little repetitive.
"VIVID" by fairy fore from FFU(FFU is shit except for this song) - if you look up the lyrics for this song on animelyrics.com they're pretty non-sensical but it's still a song that always puts a smile on my face.
"Lost heaven" by L'Arc~en~ciel ( it's from D.N.Angel)
"GROOVY", "Ashita no melody" and "Hitorijime" from CCS
"So Young" by the corrs
"Congratulations" and "Kiss kiss kiss" from Ah! My Goddess round off my contribution