I don't know about the other Lego games since the one I mentioned is my first Lego game. So far, it is faithful to the LoTR movie trilogy but with extra playable lego characters like Tom Bombadil, Gilgalad, Fatty Bolger, etc.
The most fun I have is with the exploration aspect of the game. It is just that I'm playing it on the 3ds and the ps3 version have much more cutscenes, items, characters and hidden areas for exploration based on what I see online.
Maybe you could try the PC version? I'm sure that'll have the missing content.
I beat Zelda 1 and got near the end of Zelda 2 but actually climbing the path to the final temple seems more like a test of attrition than any kind of actual skill, just play till you get lucky. I lost interest at that point, at least for the time being.
I got the last freeware version of Xpadder* so now I'm finally able to play all those games in my steam library that have been gathering virtual dust due to my not having a compatible controller. As a result I'm now playing the parody RPG "Breath of Death VI: The Beginning" pretty funny so far. All of the characters are undead. The main character being a silent protagonist owing to the fact that he's a skeleton without a tongue, though we hear his inner monologue and so can psychic party members. Was pleased to see a Castlevania joke reference within the first 5 minutes of play. "Troll Chief: What is an undead man? A miserable little pile of secrets! ...and bones!" "DEM: ... (Enough talk, have at you!)"
*For those who may not know Xpadder is a program that allows pretty much any controller to emulate a keyboard/mouse, with you choosing what buttons to map the keys to. So it's perfect for things like platformers and RPGs that only support certain controllers or don't support controllers at all. Continuous support and free upgrades to the newest version of Xpadder is $10 but it's the holidays and money is tight. Version 5.3 works well enough for me for now, I'd have tried it sooner if I'd known there had even been a freeware version.