Ranking the ones in the OP that I played. I'll add my score out of 10 as a bonus.
1. God of War - 9.8/10
2. Red Dead Redemption 2 - 9.8/10
3. Astro Bot - 9.5/10
4. Celeste - 9.4/10
5. Marvel's Spider-Man - 9.2/10
6. Forza Horizon 4 - 9.2/10
7. Super Smash Bros Ultimate - 9.1/10
8. Tetris Effect - 9.0/10
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9. Dragon Quest XI - 7.0/10
Amazing year. I give DQXI a 7 because I just can't get into it like I could with IX. Its a good game but it just never grabbed me, I'm going to give it another go at some point I think. And I separated it because I'm not voting it as a GOTY, so it shouldn't get any points or anything from me
My average rating given to 2018 games I played was 82.1. That's compared to the metacritic average of those games of 85.8. Both of those are high, but my average score is quite a lot lower than the meta average due to a few games I didn't like so much bringing it down. This was mainly due to two of my biggest disagreements with meta ever, as I rated SOTC a 6.3/10 and Octopath Traveller a 5.5/10 which are 30 and 28 points below their metascores respectively. Those two were my lowest rated games this year, with The Crew 2 next at 6.5/10, although that is actually 1 point higher than its meta of 64.
Also I'll just add that I think the nominations thread is pointless and we should all just do our own rankings anyway.