Thats like saying you ordered a pizza, ate the cardboard box and walked out

From the ones I've played, here's my order:

1. RE 4
2. RE 2
3. RE 2: R
4. RE 5
5. RE 8
6. RE 7
7. RE Code Veronica
8. RE 3 R
9. RE 3
10. RE 6

Resident Evil 6 is the only one, I don't like. The others are all good in my eyes.

4
2 remake
1 remake
7 in VR
Veronica
8
Revelations
0
Revelations 2
3 remake
5
6

From a nostalgic perspective I liked 2 on the n64 more than 4 on the GC at their respective releases, but replaying through them a few times through the years 4 has passed 2 for me.

The RE-Series is one of my favourite, so i'll go with this order for the mainline-entries:

1. RE4
2. RE2 / RE2R
3. RE7
4. RE / RER
5. RE 8
6. RE CV
7. RE0
8. RE3
9. RE3R
10. RE5
11. RE6

Something like this for me:

Resident Evil 2 (remake)

Resident Evil (remake)

Resident Evil 7

Resident Evil 3 (remake)

Resident Evil Code Veronica X

Resident Evil 0

Resident Evil 4

Resident Evil 8

Resident Evil 5

Resident Evil 6

I know 4 is often touted as the best one but in my opinion it really wasnt. I always found the story bizarre as it did not connect to previous entries. 4 also changed what was a tense survival horror into an action game, something  5 and 6 pushed further. 

I really did not like 8 as it returned to the 4, 5, 6 style and I spent most of the time wondering whether it was supposed to be funny or not (what was that doll thing about?). I really dont understand the direction as  Capcom have shown they can achieve real tension in first and third person, why drop that now for some ludicrous scenario with seemingly little attempt to connect to previous games (aside from 7). Im sad to say that I will  not be buying 9.