Yeah but I wanted more input :x
Well, Luigi's Mansion: Dark Moon can be a tad repetitive at times, due to some repeated mission types (just a -tad-, though). If you're the type of person who has to collect every bit of treasure in every single mission, each mission can take you a solid half-hour, with no checkpoints or ability to save mid-mission. The missions are still well-paced, though, and rewarding to complete. I'm just saying that by comparison, DKCR is a bit easier to pick up and play in short bursts. The variety of platforming scenarios in DKCR is also relentless in its creativity.
That being said, LMDM is probably the better game if you're looking to be "transported" to another world. LMDM is absolutely brimming with detail. There's a strong sense of atmosphere and place, with an intricately handcrafted feel to each area. It's not nearly as challenging as DKCR, but you can play it a bit more at your own pace, go off the beaten path a bit more and find more secrets. LMDM gets really creative at times, and is sure to make you laugh, or at least smile.
I'm not sure if this is helping. You honestly can't go wrong with either game.