Dang, was gonna recommend Potemayo, but you've got an even better show for that season. Ah well.
I will say Rosario + Vampire's a bit of an odd choice for Winter 2008, unless you really want a fanservice-heavy harem show. Ignoring, sequels, my picks for that season would be:
Spice and Wolf the original (though of course, feel free to watch the new one instead)
Shigofumi
True Tears
Mnemosyne (probably not a you show)
Even They Are My Noble Masters is probably a better fanservice harem, especially since it has an actual ending :p
All the stars in the sky are waiting for you.