I'm a big fan of GURPS. I started playing the system a few years ago, and I fell in love with it. I was hesitant at first due to friends and fellow gamers telling me horror stories about how complicated the game was. When I actually did give it a shot, I was amazed to find that -in my opinion- the game ran more smoothly than some sessions of D&D I've been involved in. I felt that way because -while yes it has more granularity than D&D general does- of the consistent nature of the rules. I'd honestly go so far as to say I found it less complicated than D&D 3rd Edition. I think what scares people is that a lot of the more in depth work is all loaded to the front of the game. Once a character is made, pretty much everything you need to know to play that character is right on the character sheet.
As someone who loves to world build, having a toolkit system instead of things set in stone didn't bother me at all. I also found that having a game which made more of an effort to make sense (give a nod toward realism or however else you want to put it) gave me better tools to world build with. Personally, I felt I had more freedom to put things where I felt it made sense for them to be rather than being so beholden to some artificial idea of encounters and things of that nature. It also meant that -for me; even though some of my games contain dragons, elves, and magic which are by definition not realistic at all- things usually played out in my head how I imagined they would if the situation were real. That was important to me because -in the past- there have been stories I've tried to tell via D&D (multiple versions) which turned out differently in actual play than I wanted them to. By that I don't mean the progress of the story so much as how the story progressed. Suffice to say that sometimes I want heroes leading armies; not fighting them.
Two of the biggest complaints I often hear about the system are "a lot of prep time" and a "lack of monster books." The first does make a little bit of sense to me if I'm talking to someone who is not familiar with the game or who has not played it. I say that because there most certainly can be a lot of prep time if you want to put a lot of time in. There are plenty of options to do so. However, there are plenty of things you need to know for a PC (or possibly a main character) which you don't need to know at all for Nameless Town Guard #4. With the information given in the Basic Set about what skill levels mean (i.e. what skill level would an expert have in a skill), knowing that situations will generally play out in my head how I see them because of the default nod toward realism, and general knowledge of what modifiers to a skill mean (i.e. -10 for a virtually impossible task), I've gotten to a point where I can honestly create most encounters in my head on the fly if need be.
The second complaint I mentioned (lack of monster books) is partially true and partially false. It is partially true because the Basic Set does not consist of a "Monster Manual" in the same way D&D does. However, within the various books (Basic Set included) there are animals, monsters, and various other creatures. A lot of the setting and genre books contain creatures which are relevant to that setting or genre; for example, GURPS Fantasy contains racial templates for elves, dwarves, and various other things. GURPS Horror likewise contains creatures relevant to horror. (On a side note, I suggest GURPS Horror even if you don't play GURPS. It's a well written book which I feel is a boon to anyone looking to incorporate some element of horror or darkness into their game.
GURPS Horror )
Partially false was probably a mild way of putting the lack of monsters complaint. The fact is that there
are GURPS supplements which are books of creatures. The whole Creatures of The Night series contains monsters. Dungeon Fantasy has a monster pdf as well. As mentioned, a lot of the books which are not specifically monster books contain creatures. If that's not enough, a quick Google search will turn up quite a number of D&D settings converted to GURPS rules. Also, keep in mind that GURPS is a toolkit system, so -if you don't mind a little work- you can use source material from other games as inspiration for things you build with the GURPS tools.
Now, I realize that sometimes you want something quicker and easier. You want something more plug-and-play. With that in mind, I'll simply link to past threads where I've talked about GURPS: Dungeon Fantasy. The idea behind Dungeon Fantasy is that a lot of the work is already done for you if you want to run a D&D/Pathfinder style fantasy game using GURPS. The first book contains templates which mimic the idea of class; the second book is pretty much the DMG, and the third book contains races and some other information. In total, I believe there are currently 17 DF products. 15 in the main DF line, one pre-made adventure, and one monster supplement. I've already talked about that here:
http://www.enworld.org/forum/general-rpg-discussion/316547-gurps-df-mirror-fire-demon.html
as well as here:
http://www.enworld.org/forum/genera...9-gurps-dungeon-fantasy-adventure-module.html
Monster Hunters and
Action! are other products which are similar to Dungeon Fantasy, but with different genres in mind. They can be found here
GURPS Monster Hunters and here respectively
GURPS Action
More than anything, I think what made me really get into GURPS was that I've come to expect quality from SJ Games. Not only quality when it comes to their products, but quality when it comes to how I am treated as a customer. When I buy a pdf, if that pdf later gets changed or edited or whatnot, I am sent an e-mail telling me so and giving me the option of downloading the new version (for free) to replace my old version. Any time I've ordered something, and it arrived at my door with something wrong (most recently, I received a Cthulu shot glass with a small chip in it,) they promptly replaced it. I know that doesn't always mean much to people, but, personally, those things mean a lot. When a company communicates with me well and gives me a sense that I matter as a customer -as a person, and not just as a number, that helps to enhance my faith in their products. When -on top of that- the products are legitimately good products as well, that makes me feel even better.
For those who are interested or think they might be, GURPS Lite is free and can be found here:
GURPS Lite
The more general GURPS area is here:
GURPS: Generic Universal RolePlaying System
...and, in the event that the idea of a "Cthulu shot glass" caught your attention, those can be found here:
Warehouse 23 - Cthulhu Dice