This band just came out with a new album in September (at right) and has three overall. They're gaining ground with radio play in the more hardcore venues. Over time, their sound has definitely improved and listening to the three albums in the order of their release is a good way to hear that.
In The Halls Of Awaiting, their first album (2002), is rougher and more visceral than their latest album, Across the Dark (2009). Although I enjoy the hard sound and driving rhythms of the first, I prefer the more sophisticated sound they've achieved with their latest and hope their evolution continues along that vein.
Insomnium is mostly death metal (there's probably a more precise term for their musical style, probably "melodic death") with a lot of Prague Rock tossed in to make it more thoughtful than the usual grind-and-scream. Their use of instruments outside of the usual four-piece band (usually with keyboards, I think) is pretty great too and really ads to their overall talent.
The band has a robust, meaty sound that comes across with a lot of class thrown in. Their lyrics are strong, but their real muscle comes from their musical weave. The band began in 1997 ...