I could never get used to 2D Mario physics in a "3D" Mario game, It just feels off. Also I didn't like that it had a timer like 2D Mario games. I found myself trying to explore a level  just to realize that I only have like 30 seconds to get to the goal.

Overall I just really don't like the concept of combing 2D and 3D Mario and hope they go back to keeping them seperate.

3D World is better. Mario Kart 8 definitely has more re-playability but it also has more flaws.

3D World's main flaw as far as I'm concerned is that it takes a little too long for the difficulty to ramp up., besides that there is little that I could fault. The local multiplayer is also fantastic. Anyone who has dismissed 3D World because it isn't a 'true 3D Mario', whatever that is, needs to hand in their gamer card.

Mario Kart 8 on the other hand still has some issues; the coin is a bit silly, triple red shells are a bit common for 2nd/3rd place (and are really hard to shake), triple banana peels don't provide the protection they once did, they've nerfed the Star, the piranha plant is annoying and while the Super Horn sounds like a good idea it's too easy to use to be rewarding. I'm also not a fan of the default 100cc online and lack of proper battle arenas. The coin could have been great if is was the tool that you used to dodge the blue shells, perhaps by providing a very short quick boost (I'm thinking like a mushroom but for a much shorter duration), but make the timing quite hard. Therefore you have the risk/reward dilemma of whether to hang onto it or ditch it for a more generally useful defensive item e.g. peel or shell.

I pretty much echo these setiments.  As much as I want to love Mario Kart 8, i find new reasons to dislike it every time that I play it.  The items are extremely unbalanaced.  Today I got I was racing on Moo Moo Meadows and got a coin as my item nearly everytime.  I also had one banana peel which was immediately erased by a red shell.  The final lap I get nailed with three red shells and then just get hammered left and right with red shells, green shells, starmen, etc.  I fall all the way down to 8th place and my item pick up is a green shell.  That's right!  A green shell!  I wind up finishing in 9th and not making a single mistake except not getting the right items.  People that say that this is a big improvement over Mario Kart Wii have no idea what they are talking about.  MK8 looks pretty and controls great but has a lot more to do with luck than any other game in the series.

Not really going answer to that only because they were both fantastic and are both different in gameplay so it's not really something I would compare. Shame they both didn't launch together because it would of probably have been a much better Holiday 2013 because 2 huge titles would of launched together, but it didn't. Hopefully now Nintendo has games in the works and has been teasing quite badly that they have some unnannounce games in the works too.

Back to the question, I won't answer because I think they are both brilliant games and both different. Just so happens to be a type of Mario game.

That hasn't been my experience; thanks to the blue shell being nerfed I found that 150cc races were no longer determined by whether I get hit with it on the last lap or not, making it less of a lotto. Comeback items are also weaker so placing has more to do with skill than getting Star/Bullet pity sex.

From what I have played, 3DWorld.

SM3DW

just because platformer are more suitable to my needs

Even though MK8 is my favorite MK game of all time, I do have to agree that MK8 still has its share of BS moments... With that being said, I still think it has less BS moments than MKWii or even MKDS for that matter!

Yep. MKWii was way more balanced and items (with the exception of bullet) were more fair.

3D World, because MK8 keeps giving me single mushrooms, green shells and coins when I'm in 10th place. It also seems to have a system built in that gets me hit by a red shell immediately after I fire one myself, most of the time.