These are just for starters, if you get addicted (you will,) then the list becomes alot more extensive. Secondly, call of pripyat, with 'i work alone' 1.2, an older mod, but as above, gives you a pretty awesome 'vanilla' although, you dont need to mod cop for it to be awesome and bug free (ish) unlike SHOC, but it will help, especially with weapon graphics, and horizon distance. itll provide you a great bug free vanilla play of shoc, with some great additions, but without any of the overwhelming stuff alot of the major supermods add. Shadow of chernobyl, with the 'SHOC starter 2017' mod.
Youll get quite a cross section of answers, but my advice is this: