BlazBlue: Calamity Trigger was a game with a lot of potential, but some reasonably unbalanced characters limited its actual playability. This new version, BlazBlue: Continuum Shift is a much better game, with many new characters and tweaks which seriously improve the overall experience.
Also, it is supported with lots of DLC and will be upgraded to for free in a few months to the new Continuum Shift 2 version, so there is definitely longevity in this title.
If any of you love fighting games to be fast paced and more centred around offence, this is the game for you. If you think Street Fighter 4 is getting a bit boring, and its playstyle just isn't quite keeping your interest anymore, pick this up – it's sure to push your buttons.