Ford and Connery is what makes raiders such a great film.  Also that film had the best action sequences of all the films in the series in my opinion. 

I assume you meant to say The Last Crusade?

Last crusade (Sean Connery is a legend).

The Indian in me will say temple of doom.

Raiders of the Lost Ark has the best balance between action, romance, and comedy. I still love the boulder at the start, the fight at the bar, bringing a gun to a swordfight, the kiss on the ship, and the finale with the Nazis getting obliterated.

No other Indiana Jones quite struck that balance.

My full ranking:

1. Raiders of the Lost Ark
2. The Temple of Doom
3. The Last Crusade
4. The Dial of Destiny
5. Temple of the Crystal Skull

Kingdom of the Crystal Skull is the best.

Someone throw internet stones at that man!

Raiders is a masterpiece.

The rest are movies.