SPICE Model Links
From LTwiki-Wiki for LTspice
Begin by Googling 'part name' "SPICE model", usually it's enough.
Large list from elektronikschule.de
Links to many companies' SPICE models from emwonder.com
Opamp, Voltage Comparator, Voltage Regulator, Voltage Reference Models Use caution, may be a copyright violation.
Utilities
Manufacturer sites
Coilcraft Inductors
Diodes.com
International Rectifier
Littelfuse Thyristor SPICE Models
ONsemi