Previous versions of Skyrim have sold best in North America, a region where Switch is very strong.

FIFA on the other hand is more of a European thing, and Switch isn't doing as well there.

There also seems to be more buzz surrounding the former.

Well, fifa sells more than 10 million every year. it is much bigger than skyrim nowadays.
Id bet on fifa.

Too hard to tell but it's definitely competitive ...

FIFA 18 is a new game releasing on a system where the console manufacturer is weaker than ever in the region which the game performs best in and Skyrim is an old game is releasing in the strongest performing region of the console manufacturer which is the game's best performing region ...

I think FIFA 18 might top Skyrim for the Switch all things considered and portability is not so much of an argument in favour of Skyrim as it is for FIFA 18 since the feature is inclusive to both ... (Skyrim is also going to undergo a second rerelease which will water down it's sales even more.)

To be clear, Nintendo has had weaker periods in Europe.  The NES, SNES, and N64 underperformed there.  

The bigger problem with Fifa is that the Switch version is universally recognized as objectively inferior to other major versions.  That it looks a bit better than the PS360 version as EA declares doesn't change that it is missing the big new feature for the game.  As a result, I've seen a lot of rolling of eyes with regards to Fifa.  Skyrim, on the other hand, has had a pretty good reception.  It looks like a much higher effort port, is feature complete, and seems to be at least derived fromthe Special Edition release. I've seen much more positivity with Skyrim.  And the title could very well experience some synergy with Zelda as a lot of people who loved that game and loved having it on the go may be looking for a similar experience.

Honestly, a better comparison would be NBA 2k18 and Skyrim, two feature complete and good effort ports.

I think it all depends on who gets more marketing.

I am going to say Skyrim for now.

Agreed, Skyrim seems to be getting a lot more positive attention thus far, and since Zelda was the Switch's flagship game from launch right up to Splatoon 2, that naturally generates a player base who will want more experiences in a similar vein.

I also think portability will benefit Skyrim more, as having a AAA open world RPG playable on the go is more novel and impressive than a sports game on the go.

Definitely Skyrim.

Its a mega popular game and there won't be an updated version a year from now.

I feel a game like Skyrim also appeals to the Nintendo audience more.

I am fairly certain Skyrim

Fifa will do great in Europe, but Skyrim will be a far bigger seller in USA, Asia, rest of world.

I honestly think SKyrim will do insanely well on the Switch, as a game it has such a giant fanbase and the reality is there are probably a very high amount of Skyrim fans who would like the concept of playing it while on the train or in the doctors office waiting

I think Skyrim will have a way bigger opening weekend than Switch Fifa and end up outselling it by at least 2-1

no, Fifa Switch will sell a lot more than NBA 2k18.

NBA 2k18 will not be in the ballpark of either Fifa or Skyrim. It'll probably end up sales wise like:      Skyrim >>>> FiFa >>>>>> NBA 18

ehhh you sure about that? I don't think SKyrim is as far behind Fifa in yearly sales as you imply. And on the markets were Skyrim has focused, particularly PC, It has to still be pushing a few million sales a year

The Fifa comparison is not really fair if you're literally comparing EVERY edition of Fifa (its a yearly franchise) against Skyrim, a 5 year old game

It's like- yes, Madden probably has been selling more than Skyrim the last few years- but it is an annual series.

That said a revised Skyrim on arguably a new market? I think it has a big advantage over Fifa to general audiences everywhere except Europe