For someone looking to branch out...

[Azgulor]

If you like d20 fantasy and want to experiment with modern or sci-fi, I'd say stick with d20 and move to the d20 Modern or Future book. If you are looking for a rule-set other than d20, I'd suggest GURPS.

Seconded.

Grim Tales would be another d20 alternative.

 

[smilinggm]

My Suggestion would be Traveller!!! Traveller is available in both D20 and non D20 Versions.

 

[Rasyr]

What game system would you recomend for someone who likes D&D but would like to try alternatives. Not necesarily fantasy, possibly sci-fi/cyberpunk but open to almost anything. Any ideas for a system which is relatively quick and cheap to get into (if the CORE rulebooks number in the 2 digits, I'm not interested )?

HARP - you can get HARP Lite (96 page pdf) for free from http://www.harphq.com

You can also get the full rulebook (192 pages) in pdf for $10 or print for $25. It contains everything you need to use the system.

HARP has its own setting coming out in a month or two (Cyradon), and ICE is actually going to be doing HARP (and RM) versions of the Freeport (Green Ronin) line starting later this summer.

This fall, ICE will also have a sci-fi version of HARP coming out. It will have its own default setting, plus 2 other companies have already licensed it for use in their own sci-fi type settings.

If you want to cyberpunk, there is always CyberSpace by ICE. It is currently only in pdf format (just rereleased a few months ago). It has a small number of products under its belt and is a pretty good system overall.

 

[MonsterMash]

Suggestions are:
BRP Call of Cthulhu (easier too get than the D20 version)
Paranoia XP

If you want a D20 game then
D20 Modern
Conan RPG

 

[IronWolf]

As others have mentioned Shadowrun might be a good one to try... It's been years and years since I have played but it was fun back then.

 

[Silverleaf]

The d6 system is pretty adaptable and you can get by with just one book. It's also very easy to learn. Well at least the old WEG Star Wars system is, now they've got several d6 books out and supposedly they're at tad bit more involved (I haven't seen them yet). Anyway, it's something worth looking into.

 

[der_kluge]

I'll add a second vote for HARP. The HARP Lite is free, and the .pdf is only $10. Everything you need to play. Heck, I think it's more than you need, personally.

And Freeport is going to be coming out for HARP. How cool is that, huh?

 

[Crothian]

well, the big games are mostly covered. So let's go to something less known like A-State and Savage Worlds. A-State is gothic, sci-fi, horror. It has one of the most interesting setting I've read about in a long time. THe stting is one city and nothing outside the city really seems to exist. Savage World is a little more gerneic, but the really cool thing is the setting books. The rule book is easily usible by itslef, but there are different setting types for it.

 

[scourger]

Any ideas for a system which is relatively quick and cheap to get into...

Here is my recommendation for the single best game that will meet your criteria: Omega World. It's d20, built ont he 3.0 system. It presents a complete game in about 40 pages. Something many, many other games fail to do in several hundred pages. It truly captures the fell of the classic Gamma World game. I believe it is the best d20 game I own or have owned. It's a steal at $10.

Here's a link:

http://paizo.com/dungeon/products/issues/2002/v5748btpy72wv

 

[AIM-54]

Let me put my vote in for Shadowrun. All you need is the main book (and indeed, it's all I'd recommend for a new player/group to the game) and you are more than set for hours of fun.

If you're looking for fantasy, all I can say is I've had a blast with both HARP and Exalted, but my experience with them is quite, quite limited.