I often use the free Studio Instruments that come with the free Cakewalk by BandLab. I don't use them in Cakewalk, BandLab, BIAB or RB. I use them in Reaper because that's what I am used to and productive using.
SI Drums, SI Strings, SI Bass and SI Electric Piano (which doesn't have a plain old piano) For SI Bass you may need to move your bass midi file up an octave but it's no big deal once you get the hang of that.
For piano I often use the free Keyzone Classic by Bitsonic.
For a slightly more complicated structure but way more choices I often go to SampleTank 3.
If you are not worried about price at all check out the Native Instrument offerings.


Does the noise in your head bother me ?