These are some of the most popular websites for downloading presets. The presets listed here are a mix of PV2012 (Lr4/5) and earlier (PV2010/2003), and I’ve split them into Free vs. Paid to help your search. If you know of any more that you think should be included, please let me know. Enjoy!
Free & Paid Presets
The Preset Factory – 25% off with LRQUEEN25
Only Paid Presets
Really Nice Images (film emulation… very good!)