Point-buy character creation, 3d6-based generic ruleset adaptable to any genre.
Ranked in these QuestionsQuestion Ranking
Pro Great sourcebooks
GURPS sourcebooks are famous for being comprehensive guides to the settings/genres they describe, to the degree that even people who don't play GURPS find them useful.
Pro Modular rules
GURPS can be as crunchy as you like, with rules available to cover any situation, but at its core, there are only about three rules you need.
Pro Character mortality
In GURPS, characters can be killed by a single blow to the head with a wood plank. For gamers seeking a more "realistic" level of mortality, GURPS is your game.
Pro Long character creation creates a bond with your character
Spending a lot of time creating your character also helps with creating a bond with them. This way you will be more encouraged to keep them alive than going around doing dangerous things which would most likely end up killing them.
Con Long Character Creation
The lion's share of the work in GURPS is front-loaded: characters are built on points, pieced together with attributes, advantages, disadvantages, quirks, skills, powers, spells, cybernetics, and whatever else your game requires. Expect to spend easily an hour or more creating your character.