Both are currently the most popular kart games in the market and both have similar mechanics and gameplay 

Now Nintendo offered a free trial for Switch online I could finally try CRT: NF, and it gave me the idea for this thread 

So, which one you like the most and why. Which one would you recommend for someone?

I enjoyed CTR much more than I expected, its a very fun game.
That said, this is no competition for me, MK8 is the best kart game ever and a must-play for anyone.

I like the simplicity of MK8

Mechanically I would put them at a similar level, and I feel both games can learn from each other, I favor stuff like the drift and boost usage from Crash, while MK has a better feel in its control and general race tracks design.

They are on par in terms of content I think, Crash has the cool story mode, while Mario Kart I feel motivated to go through the Grand Prix Cups.

In presentation Crash can't touch Mario tho, neither music score, art direction or character design, that gives the edge overall to Mario Kart.

I think CRT have more difficult maps with better elaborated shortcuts. You need more knowledge and ability to master CRT tracks than to master MK tracks 

About art direction, I also feel CRT have more elaborated scenarios and more detailed character design. The CRT maps are gorgeous with more things happening in the background, more vibrant colors and more complex textures and assets 

One thing that bugs me a bit are the loading times, they look bigger in CRT compared to MK

But I really miss a story mode for MK8, I understand most use it for the multiplayer, but I like singleplayer and I beat all maps in 2 days and then felt unmotivated to play more

CRT story mode is harder, has time trials and CRT challenges, and since it takes more time to master the sinolayer playthrough is lengthier 

I never played the remakes but the originals but Crash fucking sucks. His design is trash. Arms sticking out of his head! His games are trash. They are so flat, simple and straightforward (literally) and boring. CTR on PS1 I heard all the hype then I played it and it felt like every failed Kart racer to me.

Still picking MK8DX but above that, the best Kart racer is not even in the damn poll!

This is! A lot of ideas in MK8 they got from this game. Plus it has the best OST of any Kart racer with remixes of some of the best SEGA has to offer. Panzer Dragoon. After Burner. Shinobi. Golden Axe. Het Set Radio. Skies of Arcadia and more tracks/characters and music. You can also race as a SEGA Dreamcast controller!

From my experience, the better shortcuts are more in exceptions rather than being the norm with Crash, there being more to master in Crash comes down to the boost and drift rather than the tracks themselves being complex I feel.

The thing with art direction for me is, by default Crash may have more detailed visuals just based on the fact that it was made with a more powerful hardware from the get go but that doesn't translate to a more aesthetically pleasing or better looking game to me, there is more detail to the character models, but Crash's designs are very generic compared to anything from Mario, race tracks may have more going on, but nothing is as inspired or there isn't as much thematic variety as the race tracks from Mario, plus there are some race tracks where the palette clashes with one another in Crash, leading to a not very pleasing contrast.

I've only played CRT on Switch, so more powerful hardware doesn't really means anything in design. About the designs being generic, I don't really feel it. Thematically both have similar stages and concepts, Crash just is more detailed and have better textures

I played all the original sixteen CRT tracks and all them have shortcuts, some obvious others not really. They changed some tracks to add new paths, it was a nice addition

You need to turn and drift in the right moments to take fully advantage of the race, I never experienced the same in MK. I don't think tracks in CRT are complex, they are quite simple, they are just better designed from gameplay experience. In reality I think MK8 has more complex tracks, with more paths and more space to choose where to drive, but it ultimately doesn't translate in a more exciting race, I feel like every race in MK8 is the same, the only thing that changes are the items you get 

Jump in the right moment to get a speed boost is quite satisfying, make me keep replaying the same track again and again to go through the time trials, never felt this playing MK8

I'd go mk8 over crash. My main issue with crash is that most of the newer courses are bad. I might be in the minority here but I think the drift system in crash is overly complicated to pull off, I don't gave a problem doing it, but it seems more complicated then necessary, which goes against the idea that kart racers are meant to be more accessible. I remember trying to play crash with friends and they all hated it because they couldn't get into it.

As a whole CTR, it is fun to master but also the experience for me was great I enjoyed the monthly new content it gives me reason to play and come back bit like smash, plenty of people return with a new update/character stage. CTR was my 2019 game and spend 612 hours with the game.