I thought the first two LEGO Star Wars games were clever enough with the puzzles and pretty good. Not really complex or difficult but fun and good usage of the source material in the levels and cutscenes. What I played of Indiana Jones and the first Batman seemed kinda formulaic and that they were just churning them out souring interest a little. But I hear the recent games add a bit more new stuff and improve the old mechanics.
For the five bucks or so I thought the Star Wars Complete Saga was a pretty good time, fun little romp and collect-a-thon through the Star Wars movies. Superman video is making me think I'll have to pick up Batman 2.
PC versions are pretty good too. 360 pad support, etc.
i enjoyed playing the lego harry potter games with the brat. oscar pretty much nailed it.
I've played the
Star Wars ones separately, and again with the
Complete Saga edition, which is to say I've played WAY TOO MUCH OF IT. And I'm probably just a couple hours short of finishing Complete Saga to 1000/1000. There is a major flaw in the local co-op camera, where one player would move, dragging the camera with it, and it could push/pull the other player as the camera dragged to follow the moving player. In a game where players are cooperating, this rarely crops up; when playing with a 6 or 7 year old, it crops up ALL THE TIME. The
Lego Harry Potter games solve this by initiating a split-screen when the player characters sufficiently separate.
The first
Lego Batman game is pretty fun, but doesn't feel tremendously different than the Star Wars games. The
Lego Indiana Jones demo felt just like the
LSW games, so I passed. I am pretty curious about
Lego Batman 2: DC Heroes' open-world aspects though.
And now I'm curious about the
LotR game...

How's the DLC for Arkham City? I bought the standard game on Origin last year, still haven't played it. Now it's $7.50 on Steam w/all DLC. If the DLC is good, I should probably just get that so I'll have the complete experience when I do play it hopefully soonish.
The
Catwoman DLC is a lot of fun. The additional, mid-game missions are good, she has a different movement method, and it's fun to watch her move around the screen.

The
Harley Quinn stuff is new content, new maps, new powers, and that's pretty neat -- but it's short! Probably only an extra hour of gameplay.
The other stuff is costumes and Predator/Combat trials with Robin and Nightwing, isn't it?