You will always have problems with the 'public' torrent sites....Piratebay is probably the worst...plenty good torrents but plenty infected ones too.
You get what you pay for.....i.e. feck all! LOL
depends what you want to download as well.
I use a 'private' site where you occasionally pay typically $25 for 500-600Gb of download....and its all quality stuff, haven't had a virus in five years, most films are at twice the basic resolution, i.e. 1.4Gb or so instead of 700Mb (makes a big difference even on a laptop screen) or BluRay and it all comes down compressed - I extract using WinRar which has always worked extremely well. But plenty music and s/w as well.
Using previous versions of Mtorrent (or mu-torrent to give it its correct name) is advised as mentioned, because later versions allow detection by your ISP which will result in throttling.
I consider $25 a fair price for 300 or so films personally, but if you really want something for nothing then expect problems from time to time. On a 'private' site you get to know the good uploaders and can get help whenever you need it....well worth it IMHO.