bitflipper
There are places where you can buy individual snare samples. My favorite drum sample shop is Drumwerks, which offers a large selection of individual kit pieces. Here's their snares page. They're typically 5 bucks apiece, plus they have bundles of snares such as the Pearl Power Pack with 50 snares - gotta imagine one of those will be what you're looking for.
 
Drumdrops is another vendor to check out. Analog Drums sells kits, but they're cheap and you can pull any of the drums out for individual application.
 
As noted previously, there are many options for beefing up the snares you already have. Truth is, real-life snare drums never sound as good as they do on records. That's all engineering magic.

Thanks bitflipper ,for the lead on the Drumwerks sample shop. Nice sample packs over there.
Do they ever run sales? or have codes?

AD2 has some great deep snares. I usually link two or more and mix to taste. 

Thanks guys for the feedback.  Im using the very basic Sonar X3 as a DAW and it only ships with Session Drummer 3.   I dont mind dragging in drum samples and saving the kit as a custom kit.  If i could find some good snare sounds that is.     I haven't had any luck in trying to improve the snare sounds as Bflat5 was asking.   I did a quick google for "snare samples" and see if there is anything decent i can download.    Or, I'll check how much Superior Drummer is as suggested by Bapu.  I wouldnt be in a financail position to buy expensive drum software for the sake of a snare sound.    I find Session D nice n easy to use so its just a matter i guess of dragging in some decent samples.    Thanks guys.  Some helpful stuff there :) 

Yes, Drumwerks has run sales in the past, and have weekly specials. Once you make a purchase you'll be on their mailing list and get tipped off on future deals. But really, at $5 a pop - that's the price of one drumstick. Why wait for a sale? 
 
P.S. I see that the weekly special is a collection of a dozen Ludwig snares for 20 bucks.

Sorry BitF...just saw your post bro.    Great tip man...thanks.  I'll have a look at those links and do some browsing  :) 
 

I recommend checking Platinum Samples Cakewalk SD3 kits. I have them all and these are amazing.

Great link Soundwise....nice one.  :)
 

Thanks for all the replies guys.  Some really good links there for buying kits or single shots. 

When I first read the original post, I too thought he might have been talking about Superior Drummer 3.
And thought, wow, if you can't find a decent snare drum sound in THAT drum software, then you ain't looking hard enough.  Superior Drummer 3 has dozens and dozens of snare drums, and if you can't find the one you like, you can shape and mold a pre-existing snare drum to sound exactly how you want it.  It doesn't just change the pitch of drums (in a fake sampled way), it recreates the sound of a drum as if you were actually re-tuning it.  Or as mentioned, you can also just add your own sample, to be played on it's own or in combination with an existing drum sample.  Combining and layering samples is a great new feature in SD3.

Session Drummer 3, I've never even touched.  As someone said, it's like comparing a Volkswagen to a Porsche.

bitflipper
Yes, Drumwerks has run sales in the past, and have weekly specials. Once you make a purchase you'll be on their mailing list and get tipped off on future deals. But really, at $5 a pop - that's the price of one drumstick. Why wait for a sale? 
 
P.S. I see that the weekly special is a collection of a dozen Ludwig snares for 20 bucks.

You've got a point.
Pear Collection got my attention.
Thanks Bit