So far I haven't really been into RTS games in general and the Total War series in particular, however having been tempted into purchasing the $15 Humble Bundle I now own rather a lot of them 
Any recommendations as to which would be the best one to start with please - ideally where the learning curve and user interface or dodgy AI aren't going to get in the way of the fun? Rome 2 appears to be the most recent in the pack and so presumably looks the best - or would it make more sense to start with one of the earlier games...?

Any recommendations as to which would be the best one to start with please - ideally where the learning curve and user interface or dodgy AI aren't going to get in the way of the fun? Rome 2 appears to be the most recent in the pack and so presumably looks the best - or would it make more sense to start with one of the earlier games...?