Here are the top 15 Oscar-eligible films so far this year by RT average critic's score:

Image result for rotten tomatoes score

The Oscar-eligible part removes a couple of films that were submitted for the last Oscars. Minimum of 50 RT reviews,  please correct me if I missed any:

1) Call Me By Your Name (98%, 9.1, 90 reviews) 
2) Lady Bird (100%, 8.8, 147 reviews) 
3) The Florida Project (95%, 8.7, 186 reviews) 
4) Three Billboards Outside Ebbing, Missouri (94%, 8.7, 135 reviews) 
5) Faces Places (100%, 8.7, 65 reviews)
6) Dunkirk (92%, 8.6, 357 reviews) 
7) The Shape of Water (97%, 8.5, 79 reviews) 
8) Mudbound (97%, 8.4, 104 reviews) 
9) Columbus (97%, 8.4, 75 reviews))
10) Get Out (99%, 8.3, 290 review) 
11) City of Ghosts (99% 8.3, 85 reviews)
12) Blade Runner (87% 8.2, 329 reviews)
13) The Big Sick (98%, 8.2, 236 reviews)
14) War for the Planet  of the Apes (93% 8.1, 283 reviews)
15) Baby Driver (93%, 8.0, 302 reviews)