Really into my "post rock" at the moment, I think that's the general name for this genre. Perhaps a more fitting name would be something like "Instrumental Rock".

Basically it uses the same set of rock instruments you'd expect, so Guitars, Drums, Bass, etc... Mixed with things like Keyboards, violins and often spacey keyboard/electronic effects. But the key point is that there are rarely any lyrics, so it's just about the music. It's great for just sitting and daydreaming or relaxing and spacing out a bit, especially as there are no lyrics to distract you.

Anyway, here are a few examples of some bands I'm enjoying at the moment:

God Is An Astronaut. Very difficult to choose a song for them, as they have loads of good ones, but went for this:

http://www.youtube.com/watch?v=34C41eEpM48

Mono. One of the "giants" of this style of music. From Japan and have some really nice melodies in their music. Again difficult to choose a song, but went for this one in the end because of it's great crescendo ending. Very long song though:

http://www.youtube.com/watch?v=eHx3sfvCgNU

The Butterfly Explosion. They do use lyrics sometimes in their songs. I saw them when I went to a GIAA gig last year as they were touring with them and they were very good as well.

Exxusans. Only heard them first a few days ago, but they seem to be reasonable. Similar-ish style to GIAA:

Hopefully you'll give some of that a listen and maybe enjoy it.

I have no idea if they technically fall into the category 'post-rock' but I've been listening to two bands who are somewhere around it:

*shels - The Conference of the Birds

Bossk - I

Post-Rock seems to be everywhere these days. Current obsession: Explosions In The Sky