I've been re-watching selected episodes of Koihime Musou and Hyakko, because both series are awesome.
When I'm bored I watch eps 6 and 23 of Lucky Star.
Then sometimes I'll have a bit of Horo goodness with Spice and Wolf ep 6 and the DVD ep.
Hmm... Strike Witches is always good for a laugh. I haven't finished that series yet because I'm waiting on StrikeS' DVD rips, but I could re-watch the Sanya/Eila ep all day.
Oh yeah, Baccano is great for re-watching, I find something new every time I watch an ep. I would turn gay for Firo, and then go straight for Ennis or Chane...
