I have played all in the Diablo series - bought the PC version earlier and also the PS3 version when released a few months ago.
Hence obviously I will say that D3 is as great, a whole lot of fun to play with friends online or even solo etc. The graphics are great and the loot is incredible especially on the PS3 version.
As you have multiple classes (barbarian, mage etc.) with their unique abilities, there is tons of replay value. If you havent played the series yet and plan to play D3 then highly recommend playing 1 and 2 before this to better understand the plot as they are connected.
Overall, must play as this is truly the champion of all dungeon-crawling RPGs.