Well just finished Mafia II, bloody great game and a steal at £5, it's way more gripping than GTA IV was.
Really don't understand the bad reviews, especially when GTA IV scored so high in comparison, Mafia has much better driving and gunplay. Though admittedly it lacks side missions and what not but if you want a decent story along with good gameplay then this is easily worth £20 or whatever it's priced at now.
Edit: From what I hear the second DLC is actually really good so might pick that up too.