You used to hear about the great new sound cards all the time 15-20+ years ago, but not any more. Is there any real benefit in shelling out the extra money for a proper sound card these days, as opposed to using integrated cards? What exactly do they offer that integrated cards don't?

Better sound quality
Less static noise
and the most important thing for me - usually they have amplified output for high resistance headphones.

There's also the issue of compatibility. Just because Realtek is a major name in on board sound doesn't mean that it's well supported by games. I switched to Asus mainly because Creative really aren't trying anymore. Definitely a wise move so far.

As a Creative user I can say their software and drivers are written by a semi-trained chimp called Bonzo. The hardware is solid however and I even have a Zen X-Fi purely for the sound quality. If you want Creative quality with software that actually works then look at Auzentech.

Well my new soundcard is a creative but since I never install anything but drivers I'm having a great time with it.
Integrated components are really made for business and casual users, an integrated video chip will render excel or webpages fine but be way too slow for gaming since they lack features and are really only resources for the CPU to use so the CPU has to process both the regular data and also the data normally done by a video card which is a pretty hefty drain. Integrated ones also lack the majority of fancy features that games assume you have.
Integrated sound is much the same, if you want to listen to mp3s or watch videos then integrated sound is perfectly fine (its what I'm using in my media PC and its never had a problem) but games use more advanced effects and that takes up CPU resources. Way less than an onboard video chip does but still notable and just like the video chip, an integrated sound chip will lack things like EAX and other fancy features that noone ever really uses but likes to know they have just in case.

I am using Creative Sound Blaster X-Fi XtremeGamer. Hardware is really good but Creative's driver support is so lame, they are releasing drivers just one time a year etc. But I tried removing it and switching the mainboards' soundcard and I heard the difference. Creative's sounds are clear and better than integrated soundcards also I did some benchmarks on games with creative soundcard I am getting more FPS than integrated card. Just 1 or 2 FPS but it is better :D

That's why I'm an ex-Creative user. :P As for Auzentech, I'm too cheap for that. I just want something cheap that works. My Asus card suits my needs nicely.

I've used Creative cards since I started using PCs back in the 90s. Never had one iota of trouble with them. Even being tone-deaf, I can hear the difference in quality of Expansion sound cards over integrated on-board cards. And that's on the likes of crappy old games like Doom1. Basically, you get what you pay for, as in anything and everything. Paying that few 10s of quid more for an expansion card over the freebie of on-board...really does exceed the cost.

Just to hijack this thread for a while, I'm looking for a cheap, but decent, sound card. I've just about had enough with onboard sound being the only turnoff on my rig right now. My budget isn't huge though - maybe $30? Anything that fits the budget and doesn't sound like ass? Otherwise I'll just stick with Realtek.

Something like the Creative Audigy will do the job for music, no frills for games though link
If you want my advice wait a few weeks and save up some more for a or an [url=http://www.ebuyer.com/product/166003]X-Fi

I picked up a used X-Fi Music card from PC World about 3 years ago for £25, and it has proven to be one of my best tech purchases. The quality of the sound versus onboard is especially noticeable when playing a CD in Foobar with bit-matched sound, to the extent that it is actually shocking what a poor audio solution masks on a track.
Games are also much more atmospheric, even these days with Microsoft changing the audio architecture in Vista and 7. The only downside, as mentioned above by others, is that driver releases are nowhere near as prolific as for my other hardware components.

Not even Microsoft can stop the signal. Open AL and EAX Advanced HD.

I don't know what Xonars cost there, but I'd save up for that. Not only do you get decent sound quality, but better compatibility and EAX support than Creative (which is odd, but just goes to show how lazy Creative are these days).

I have an Asus Xonar D2X, and the sound quality is lovely.
I picked it cos it was cheaper than the creative equivalent, and it was totally worth it.