FoA was the best for its awesome dialogue - my signature speaks for itself.
Emperor's Tomb was great for its action sequences and awesome soundtrack.
The Infernal Machine was ok only because Indy had to kowtow to Lara Croft style game instead of leading the genre. Plus I.F. has a difficult time running easily or stable with today's computers or their OSs.
Never played Last Crusade.
<-------I'm still waiting for them to make a game based about me and my exploits!
"There's something here!"
"Well, Well. Look at this."
"Wait till King Solomon, King Nub, & King Marduk hear about this...uhh- I'd better go tell them..." -Indy
"Run you COWARD!" -Commie Soldier