Or do you kind of just dive in for a while and fall off then move onto the next game?

Discounting games you played for less than one hour. What do you reckon your completion rate is percentage wise?

Generally, I play to beat them even going as far as pushing myself through a game where my enjoyment falls off bit if I've made it far enough I go for the credits. I fall off a lot of games very early though.
Not counting games I played for less than an hour, this year my completion rate is in the range of 50-60%.

I always go in with the intention of beating them, if its an option.

Same, I will also definitely play with the aim to complete them. 

The aim is to complete them... that doesn't always happen though.
I have a lot of "maybe I'll go back to that at some point" games.

Always with the intention to beat them.

I only play games with a conclusion/ending. (If its a fighting or racing game, I play all the characters and cars in their respective modes).

Which is why I never touch MP/online oriented games like Fortnite, PUBG, DOTA, etc.

Just this year I finished so far....

NS (6)
-Devil May Cry
-Dragon Ball FighterZ
-Dragon Quest I
-Final Fantasy VI Pixel Remaster
-Final Fantasy VII
-Mario Kart 8 Deluxe

PS4 (6)
-ACA NEOGEO FATAL FURY
-ACA NEOGEO FATAL FURY 2
-Kingdom Hearts Birth By Sleep Final Mix
-Ratchet & Clank (2016)
-Tekken 2
-The King of Fighters 98 Ultimate Match

X360 (2)
-Gears of War 2
-Sonic Unleashed

PC (5)
-Assassin's Creed IV Black Flag
-Assassin's Creed Freedom Cry
-Borderlands GOTY Enhanced
-Final Fantasy VI
-Metal Slug XX

Only if I like the game

Sometimes I don't beat them though. Stop in the last level, of after the final boss/mission but never see the credits rolling

Yeah but soon as games enter the camp of "eh, maybe later" they might as well have a funeral held and respects paid. Right? 

That's goo going for 10 months

That's good going for 10 months, I also had an epic year for completion about the same as yours. Feels good man. 

I know one thing, I'm never beating Returnal the game is too hard. I thought I was a skilled gamer but this is pretty intense.