Since HuCARDs are CARDs, there is no need to discuss them, beyond the simple trüth: CARD>CARTRIDGE for ever and ever...
IMPORTANT: It is hard for me to base this entirely on aesthetics alone...since these carts are meant to be held and used. I love the shape and size of SMS, but I wish it felt as heavy and solid as an NES cart. SMS still wins, though.

I know we are not discussing Japanese consoles, but I like the Famicom the best (there was a wide variety of shapes and colors, and I like the horizontal shape and size).
Sega SMS is the best size and has a horizontal shape, so I like 'em a lot. However, they don't feel as SOLID and as indestructible as other CARTS. I must say...I have a ton of SMS carts and they are not particularly exciting when it comes to labels. There are times I can't even figure out what game is in my SMS because I have to turn up the lights and move closer to read the label...so the labels are weakest element on SMS.
Even the "all text" design of early NA HuCARDs were a billion times better than the SMS labels. Despite the ugly SMS labels, I still think it is my favorite cart.
I love how SOLID (the heft) of NES carts, even though they are goofy-looking and huge. I guess there is an awkward charm to them, but even Atari 2600 is more practical to hold and to "grip" than the NES, IMHO, anyway.
N64, Jaguar, and SNES are too big, as far as I am concerned (for the time they were released...I like huge carts in early 80's consoles...I know, it's not fair, but the context is important for me). I think the goofy tube handle on the Jaguar is ugly, but it gets credit for at least trying something slightly different. Of course, the fact that the JagTube has not been home to cart labels annoys some people (it doesn't bother me...)
I never owned the RCA Studio II, but the cart looks pretty awesome (however impractical it might be). It looks like electronic gear used by Soviet Cosmonauts...and there is a certain utilitarian charm in *not concealing* the raw metal bolts and contacts.
I just love all these carts, really. Atari/Coleco/Intellivision all felt great to use and hold, even if they suffered from the "hollowness" that I spoke of earlier.
The Odyssey 2 handle looks goofy as hell, but I bet I would absolutely LOVE to actually use it.
NOTE: The above image has been recycled 38 times over the years. Trüe storie.