So, believe it or not, I'm not a very avid gamer. I'm definitely more traditional in my tastes, leaning towards my NES collection just as often as I reach for the Wii. For me to sit down and obsess over a game is a very rare occurrence. The last few games that really nailed me down in front of the tv have been Rock Band, Legend Of Zelda: Twilight Princess, and most recently Lego Indiana Jones.
I really dug the Lego Star Wars games, but Lego Indy totally knocked it out of the park. Maybe it's that Indy is a bit more suited to the adventure game than some of the Star Wars prequel characters. Maybe it's just that the game looks better and plays smoother than the Star Wars games. I think it's probably all the little things that make this game so much fun.
For example, the loading screens between levels are flat map backgrounds, but instead of a progress bar slowly crawling along the bottom of the screen you get the familiar red line from the Indy films connecting his voyage from point A to point B.
The character specific abilities and accessories are much more varied, and so true to the characters too. Indy has his whip, of course, and female characters can jump higher because they are more "nimble", and small characters like Short Round are still the only ones who can access secret tunnels. But now there are mechanics (who fix stuff, duh), guides (who have shovels and dig up treasure), archaeologists (who carry books to help decode puzzles) and a slew of other clever and unique little tweaks on all the things I loved in Lego Star Wars.
I don't even mind going back and playing the same levels again on free play, which is a rare occurrence. I usually don't care about unlocking all the hidden stuff in games, or getting 100% complete, but the Lego Indy stuff appeals to the kid in me and I want to see what clever little thing they've got waiting for me next.
Seriously fun stuff. Great adaptations of the films. One of the best games I've played in a long time. Sit down and play it if you get a chance.