AliExpress.com - great for bulk orders from China.
Banggood - great for bulk orders from China. Sells like an eBay marketplace. Marginally more reliable and sometimes much faster than AliExpress.
Amazon - equipment is often cheaper
TechnoBots - electronics and some very nice hardware components, gears, pneumatics, chains, pulleys
Micro-Tools Europe - Small tools
RS has most things, more professional, usually more expensive (especially for small orders).
Rapid Usually cheaper than RS or Farnell for run-of-the-mill parts. Website search often sucks - try to get a paper catalogue
Online Components Has a pretty large catalog of electronic components, much like Digikey or Mouser
Mouser USA based but free shipping. >£50 Like farnell but often a little cheaper.Digikey USA based but free shipping >£50. Like Mouser but bigger range, typically a little more expensiveTME.eu electronic components, cheaper than RS, next day shipping is £5.20.
Toby UK Specialising in board-board and signal-board connectors. Potential UK supplier of hard-to-find extra long pin headers as used by the Arduino platform.
Seeed studio
Sparkfun electronicsLinkSprite Open source electronics, pcDuino, communication modems.
Tindie - electronics marketplace like Etsy
Oomlout Arduino & DIY electronicsBits Box - electronic components
Hobby Tronics Yorkshire based well sorted mail order, sparkfun stuff, their well made own versions and components.
Barend Hendriksen Holland. Interesting RF parts.
Keytronics Obsolete IC supplier mail order, can also be found with small parts at radio rallies.
mark5 Obsolete and hard-to-find electronic components.
MMS Electronics - SPI/I2C graphic LCDs (pricelist)
Mega Electronics PCB-making supplies. Their products are also sold by Farnell and Rapid but may be cheaper from Mega.
Modtronics Australia PIC32 Wireless Development Boards. RFM69HW breakout boards and modules.
Smtstencil Cheap polyester SMT stencils. Quick service.
Goodwill, Ultraleds, Led-tech - A gazillion kinds of LED
Sure Electronics (China) Interesting selection of electronic stuff.
Ciseco Microcontrollers, radio modules, Raspberry Pi expanders
Proto-pic good for soft-circuits stuff and various electronics
Tayda ElectronicsShenZhen2U Cheap Chinese PCBs - about 3 weeks delivery
Tinker Tailor electronics stuff for wearables
