I'm a fan of Samsung SSDs, but 120GB is just too little these days. It's worth spending a bit more for a 250+GB drive, even if it isn't a Samsung.
Bad things can happen if Windows runs out of space at the wrong time. My oldest's machine ran out of space as it was writing to the registry... I was able to recover, but only thanks to my ninja PC skills (and 30 years of experience) and some lucky Google search results. I just upgraded my other son's PC from a 120GB Adata to the 500GB Samsung EVO 850 (The $150 eBay deal a week or so ago); he was pushing the limits on the drive, with less than a gig to spare.
Like PSUs... Boot drives are simply not worth cheaping out too much on.