Eh, after a couple years with a paid GS subscription I switched to a higher quality paid service a while ago. Grooveshark's brutally bad album support, combined with the penchant for content just vanishing from my playlists, rendered the service nearly useless to me in the long run.
AFAICT, it's most unique feature was community radios... a feature I'd love to see replicated elsewhere but is, as for as I know anyway, still unduplicated.
I've personally switched to Google Play Music, mostly out of sheer convenience. Previously I used just the free service to upload my own stuff... the amount of storage they offer is pretty huge and the sync app isn't too bad.
Then I decided to give All Access a try and discovered a pretty enormous selection at a decent price (double what I was paying for my GS subscription, but with a properly curated library that doesn't disappear randomly), with full offlining support to my phone.
Overall I've been incredibly happy. I'm sure other services are as good or better but I've not found a reason, yet, to shop around so I figure I'll stick with Play for the foreseeable future.
AFAICT, it's most unique feature was community radios... a feature I'd love to see replicated elsewhere but is, as for as I know anyway, still unduplicated.