46) The nightmares' worst nightmare.

They tried to seal him away, but when all hell breaks loose he awakens once again.

From Mars to Hell, from Hell to Mars.

The last hint gives away Doom, combined with the second hint I guess it is the reboot from 2016. And yeah, the nightmares' worst nightmare is fitting. :)

47) Memes about memes.

And an invincible cyborg.

And don't forget the nanomachines (son).

RULES OF NATURE

AND THEY RUN WHEN THE SUN COMES UP

WITH THEIR LIVES ON THE LINE

ALIVE

*cough*

Metal Gear Rising

I'll give #48 until tomorrow, and post it together with #47 which had already been guessed previously. Still, I'll a fourth hint, and add two further games.

48 - Whack people with weapons such as barbells, arcade cabinets and tuna fish.
Hint 2: But there's also guns to be found. Not stuff that should've been on a cruise ship.
Hint 3: To be honest though, those weren't have been on the ship if the pirates and their one-eyed captain didn't bring them on board.
Hint 4: Those pirates are there to kidnap the 'President's' daughter.

I'm a bit late to the party, so here's my first entries:

50: Probably the best PC-exclusive beat'em up

49: One of the earliest RTS games and one who massively popularized the genre

48: No transformations in this entry of the series despite it being a series staple

47: This early 3D PC game is mostly an ego-shooter, but also an adventure game and has some strategy mixed into it.

Okay so, more hints. #42 was guessed already, but I don't think it's time yet for #41 so just extra hints for #44 and #43.

44 - About halfway through this game there's a racing level where you have to reach a well-known hero before the villains do, which is silly because in canon this hero is one of the most powerful people in the galaxy.
Hint 2: Surely, this master should be able to take on a handful of 'biker' thugs, but anyway, chase scene it is.
Hint 3: This chase scene level, level 6 of 10, takes in a very famous location from the movie. This is also this hero's home planet.

43 - This game features a couple minor vehicles, which you'll use in a supporting role next to the primary vehicles, which are sometimes based off cars and vans from real-life TV shows.
Hint 2: They look like how they look in the shows too, like the orange car from "The Dukes of Hazard" and the black van with a red stripe from "The A-Team".

42 - Primary colours. Guessed by UnderwaterFunktown - Pokémon Blue