I highly recommend RTR Platinum. It is a conversion of RTR 6.0 to play on RTW 1.5. It gets rid of lots of bugs, and is a very good game. I also recommend some extra mods to put with RTR Platinum. Metropolis and Naval Mod really improve gameplay and keep the campaign faster-paced. And I think RTR Platinum comes with Marcus Camillus's Roman Leadership mod, which greatly improves gameplay and traits for the Romans.