Remember back in the previous decade when a big drive was 500GB. I bought Seagate ST3500s for around $50 and all had a 5 year warranty. They have went past their warranty and I finally had to replace 2 in separate machines. I definitely got my money's worth out of them. Some of them are probably 8 years old.
I'm replacing them with WD Blue 1 GB. They have a shorter warranty but great for the price. Oddly the only drives I've RMA'd are WD Blacks.
By the time these WD Blues are out of warranty, larger SSD should be even more affordable.

I will eventually upgrade the OS drives since those 500GB SSDs are under $200. Is there certain brand of SSD better than others?

 Just rebuilt my music rig, and added a pair of Samsung EVO SSD's that I got from Newegg at a decent price -
performance is incredible!!

I replaced my boot drive on my laptop and my daw with 500gb Samsung Evo's.
I agree with rivers88, the performance IS incredible!

The difference is very noticeable to me. 
I used an Evo 820 for the C drive in my DAW but stayed with a standard 7200 drive in the office computer I re built. The SSD drive computer is at the log on screen in 4 seconds. The office computer grinds away forever before getting there. 
The Evo is just 128 GB and was around $100. You don't need any more than that for your C drive. I see little point in the bigger SSD drives unless it's a laptop, until the price per Gig comes down a lot more. 
For data the old school 7200's are still best bang for the buck. But SSD certainly the way to go for the OS