I've played GURPS for several years, and think it is one of the best RPG systems. Needless to say, I don't agree with all of what nsruf wrote.
I personally don't think there is
one true RPG system that fits every need. Pick a system that fits the type of action you are trying for.
There is a
fairly long list of GURPS books that have been printed. You can easily get
complete and current errata for all of their books online. Playtesting of their materials is avaiable to any
Pyramid subscriber, and is fairly easy to participate in. The playtesters use a newsgroup to make comments in, a lead playtester helps the author's sort through the comments.
The GURPS
historical books can be very useful regardless of what game system you use. They are well researched and concise descriptions of historic or mythic periods which can help you fill in your game background regardless of what system you use.
The GURPS setting books (
CthuluPunk,
Technomancer,
Fantasy) tend to be more involved in rules, but some people still find them useful.
The GURPS Rules books (
Basic Set,
Magic,
Grimoire,
Martial Arts,
Vehicles) are typically only worthwhile if you are running a GURPS game.
As a player, it would be easy to get by with just the
GURPS Lite ruleset. Many GMs find it useful to pick up between 3-5 other supplements to flesh things out. If a player plays a Mage, they will most likely quickly find themselves wanting GURPS Magic.
Now, about the rules themselves.
As a GURPS GM, you
must review every character submission to make sure it is appropriate to the type of game you want to play. It usually works best to work with a player to create the type of character they want, so that a total rewrite isn't required. You must be willing to say No to characters you don't like.
Don't use all the rules. Let me repeat that: Don't use all the rules. Only use the rules that are appropriate for your game and the level of detail your are comfortable with. You can even switch based on circumstance. Many people use basic combat when it is a minor fight (makes things go faster) then switch to minitures and use parts of advanced combat for dramatic fights.
Creating a character requires lots of addition, some table lookup, and a very minor amount of division. There are
a wide selection of computer aids available for the system, including multiple character generation programs.
I totally agree with nsruf that points are not an effective measure of character balance. It is a common misconception that they should be. It is a much better indication of how unusual the character is than how powerful.
I disagree that it causes more munchkinism than other systems or even less complex. Look on the boards at all the requests to min/max D20 characters. You get people recommending specific combinations of classes, PrC, skills, magic items and such. Personally, I find D20 much more open to munchkinizing than GURPS.
It is much easier to customize a character than in D20. Given a good GURPS GM, it is also much easier to run a character in GURPS than D20. If you can describe your actions, the GM can usually fit them to the GURPS mechanics without problem. I always feel like I'm in a straight jacket when playing D20 because I have to wait to 'level' before adding any skills to a character. If I spend a month living in another country, I should be able to learn a smattering of the language.
Combat in GURPS tends to be much more gritty. Getting outnumbered in GURPS is a
lot more dangerous than in D20. If you feel that D20 is too cinematic, you should probably investigate GURPS.
A bad GURPS GM can totally wreck the enjoyment of the system. It sounds as if several people have already met them. A good GURPS GM can make it a lot of fun.
[ Edit: Fix URL formatting. ]