Some DAWs (often costing a lot more than Reaper) do come with some software instruments bundled in - so you would get them, whether you wanted them or not.
Reaper has very few (3?) bundled software instruments so you can pick and choose the ones you want, from hundreds of third-parties. And you can pay anything from nothing to hundreds of $.
One good place to start is to purchase (£6 max) any issue of Computer Music magazine, printed or digital. This gives you access to its FileSilo from where you can download a wide variety of instruments and FX.
Here is the list, from cm248:
Code:
Folder PATH listing for volume CM248
Y:\CM PLUGINS
+---Mac Software CM248
| +---Effects
| | +---32-bit only
| | | +---Artillery2 CM Edition
| | | +---KR-Delay CM Edition
| | | +---KR-Reverb CM Edition
| | | +---Kuassa Amplifikation CM
| | | \---MeldaProduction MHarmonizerCM
| | |
| | +---Acon Digital CM Verb
| | +---Acustica Audio Pink CM
| | +---Auburn Sounds Panagement CM
| | +---Audiffex STA Enhancer CM
| | +---Audio Assault BassAmp CM
| | +---Audio Assault GrindMachine CM
| | +---audioD3CK SunRuys CM
| | +---Audiority TS-1 CM
| | +---AudioThing The Orb CM
| | +---AudioThing ValveFilter CM
| | +---Blue Cat Audio FreqAnalyst CM
| | +---Cableguys WaveShaper CM
| | +---D16 Group Frontier
| | +---DDMF CM EQ Pack
| | | +---IIEQPro CM - 32-bit and 64-bit
| | | \---LP10 CM - 32-bit and 64-bit
| | +---Dotec-Audio DeeMonitor
| | +---eaReckon CM-COMP 87
| | +---eaReckon CM-EQUA87
| | +---HoRNet DrumShaper
| | +---HoRNet Graffio CM
| | +---HorRNet Fat-FET
| | +---Ignite VST Areena
| | +---Ignite VST Vice One
| | +---Inear Display Eurydice CM
| | +---Inear Display Litote CM
| | +---JST and Boz Digital Labs SideWidener
| | +---Kuassa PreMix CM
| | +---Lindell Audio 6X-500 CM
| | +---LiquidSonics Reverberate CM
| | +---LVC-Audio Transector CM
| | +---Mercuriall Audio Software U530 CM
| | +---NYRV Systems Agent CM
| | +---Ohm Force Ohmygod!
| | +---OverTone DSP AF210-CM
| | +---OverTone DSP PTH-2A Program EQ CM
| | +---Photosounder Spiral CM
| | +---PSP Audioware cmDelay
| | +---Rob Papen RP-Distort CM
| | +---SKnote Snap
| | +---Sonimus Satson CM
| | +---Subsonic Labs Wolfram CM
| | +---Tek'it Audio CrossDr CM
| | +---ToneBoosters Barricade CM
| | +---Toneboosters Sibalance CM
| | +---Unfiltered Audio G8 CM
| | +---Vengeance-Sound Philta CM
| | +---Vengeance-Sound Scope
| | \---Venomode Maximal 2 CM
| |
| \---Instruments
| +---32-bit only
| | +---Big Tick RhinoCM
| | +---LinPlug CM-505
| | \---Synapse Audio Plucked String
| +---AudioRealism ADM CM
| +---AutoTonic CM
| +---brunsandspork Grooove CM
| +---Cableguys Curve 2.6 CM
| +---DopeVST Bass Engine CM
| +---DopeVST Beat Machine CM
| +---Eisenberg Einklang CM
| +---Expert Sleepers XFadeLooper CM
| +---Humanoid Sound Systems Enzyme CM
| +---Kirnu Cream CM
| +---Klevgrand Enkl CM
| +---KV331 Audio SynthMaster CM
| +---LinPlug Alpha CM
| +---Loomer Cumulus
| +---Madrona Labs Aalto CM
| +---Monoplugs B-Step CM
| +---New Sonic Arts Freestyle CM
| +---Rob Papen RG-Muted CM
| +---Squaredheads Nora CM
| +---Synapse Audio Dune CM
| +---u-he Bazille CM
| +---u-he Zebra CM
| +---XILS-lab PolyKB II CM
| +---XILS-lab StiX CM
| +---XILS-lab XILS 3 CM
| \---zplane Vielklang 2 CM
|
|
|
\---PC Software CM248
+---Effects
| +---32-bit only
| | +---Artillery2 CM Edition
| | +---KR-Delay CM Edition
| | +---KR-Reverb CM Edition
| | +---Kuassa Amplifikation CM
| | \---MeldaProduction MHarmonizerCM
| |
| +---Acon Digital CM Verb
| +---Acustica Audio Pink CM
| +---Auburn Sounds Panagement CM
| +---Audiffex STA Enhancer CM
| +---Audio Assault BassAmp CM
| +---Audio Assault GrindMachine CM
| +---audioD3CK SunRuys CM
| +---Audiority TS-1 CM
| +---AudioThing The Orb CM
| +---AudioThing ValveFilter CM
| +---Blue Cat Audio FreqAnalyst CM
| +---Cableguys WaveShaper CM
| +---D16 Group Frontier
| +---DDMF CM EQ Pack
| | +---IIEQ Pro CM
| | \---LP10 CM
| +---Dotec-Audio DeeMonitor
| +---eaReckon CM-COMP 87
| +---eaReckon CM-EQUA87
| +---HoRNet DrumShaper
| +---HoRNet Fat-FET
| +---HoRNet Graffio CM
| +---Ignite VST Areena
| +---Ignite VST Vice One
| +---Inear Display Eurydice CM
| +---Inear Display Litote CM
| +---JST and Boz Digital Labs SideWidener
| +---Kuassa PreMix CM
| +---Lindell Audio 6X-500 CM
| +---LiquidSonics Reverberate CM
| +---LVC-Audio Transector CM
| +---Mercuriall Audio Software U530 CM
| +---NYRV Systems Agent CM
| +---Ohm Force Ohmygod!
| +---OverTone DSP AF210-CM
| +---OverTone DSP PTH-2A Program EQ CM
| +---Photosounder Spiral CM
| +---PSP Audioware cmDelay
| +---Rob Papen RP-Distort CM
| +---SKnote Snap
| +---Sonimus Satson CM
| +---Subsonic Labs Wolfram CM
| +---Tek'it Audio CrossDr CM
| +---ToneBoosters Barricade CM
| +---Toneboosters Sibalance CM
| +---Unfiltered Audio G8 CM
| +---Vengeance-Sound Philta CM
| +---Vengeance-Sound Scope
| \---Venomode Maximal 2 CM
|
\---Instruments
+---32-bit only
| +---Big Tick RhinoCM
| +---LinPlug CM-505
| \---Synapse Audio Plucked String
+---AudioRealism ADM CM
+---AudioThing miniBit CM
+---AutoTonic CM
+---brunsandspork Grooove CM
+---Cableguys Curve 2.5 CM
+---DopeVST Bass Engine CM
+---DopeVST Beat Machine CM
+---Eisenberg Einklang CM
+---Expert Sleepers XFadeLooper CM
+---Humanoid Sound Systems Enzyme CM
+---Kirnu Cream CM
+---Klevgrand Enkl CM
+---KV331 Audio SynthMaster CM
+---LinPlug Alpha CM
+---Loomer Cumulus
+---Madrona Labs Aalto CM
+---Monoplugs B-Step CM
+---New Sonic Arts Freestyle CM
+---Rob Papen RG-Muted CM
+---Squaredheads Nora CM
+---Synapse Audio Dune CM
+---u-he Bazille CM
+---u-he Zebra CM
+---XILS-lab PolyKB II CM
+---XILS-lab StiX CM
+---XILS-lab XILS 3 CM
\---zplane Vielklang 2 CM
And, of course, we can make specific recommendation, depending on the sounds you want, and your budget.