Depends on your budget but three suggestions:
Radisson Blu Royal Viking 4 star hotel next to central station.
Sheraton, 4 star hotel a few hundred meters from central station,
Scandic Klara, a 3 star hotel but imo still not that far behind on standard from 4-star hotels. Also close to central station.
https://www.google.com/maps/dir/Centralplan+15-1,+111+20+Stockholm/Radisson+Blu+Royal+Viking/59.3288172,18.0618585/Scandic+Klara,+Slöjdgatan,+Stockholm/@59.3315377,18.0602518,835m/data=!3m1!1e3!4m21!4m20!1m5!1m1!1s0x465f9d607c2166b1:0x5083f03c3ee137ef!2m2!1d18.0589826!2d59.3304901!1m5!1m1!1s0x465f9d608cd21b5f:0x7c069c6b454f6af6!2m2!1d18.0581268!2d59.3315127!1m0!1m5!1m1!1s0x465f9d5df9c8be97:0x853dac399a1e4557!2m2!1d18.0624326!2d59.3338316!3e2?entry=ttu