Digsby

I think I've just found Windows' killer app - Digsby - which is IM + Social Network + Email all rolled in to one (slightly bloated) app...

If you've not seen Digsby before, go check out their site...

It's not quite as reliable as some of the other IM's I've used, but it has one absolute killer feature I've never seen in anything else - the ability to reply to IM messages in the notification pop-up:

I'd never have imagined that such a simple feature would change the way I interact with IM, hopefully one day all IM notifications will provide this feature - if Adium implements this I will be much happier to transition to my Mac Mini.