I've voted to close this, with others, because it is admittedly "very opinion based." But I also have an opinion. ;)
I've been working with microcontrollers since the Intel 8080A with the Altair 8800 I built from a kit in early 1975 (ordered it January.) I've been working with microcontroller manufacturers as a small business measurement instrumentation manufacturer since about 1986. I started with Microchip quite early (the PIC16C54 through PIC16C57 were all that was available to people like me [less than 1 million unit orders, as I wasn't in the rice cooker business] from Microchip at the time.) I have been also buying from a variety of other suppliers, including Atmel and TI, and working through each of their FAE systems.
Microchip has always supported me quite well, regardless of my order level. They've treated me as if I were a million unit per year customer without a break. And they support their chips "forever," continuing to make them when other manufacturers had long since stopped making comparable parts. This is the same for their support tools, as well. I had a programmer tool that was 15 years past the date when they stopped making and selling it and the power switch became "flakey." I called them up in the afternoon, asking about getting a switch for it. The response was unexpected. Instead, they sent me a new (or beautifully refurbished) replacement unit that day, along with a box to return the old unit. There was no charge. And I received the replacement unit and the box the very next morning!
I have found chip bugs (in the PIC18F series, using their ICE2000 system to capture and demonstrate the bug) and had them redesign and refabricate the parts within 6 weeks, shipping me functioning units. Also, Microchip actually does fix their errata from time to time. Not like TI, who documents them but pretty much NEVER fixes them if there is any way to avoid it. (This can be a good thing or bad thing, depending on your perspective, I suppose.)
Anyway. I have not had a single instance, ever in 30 years of working with Microchip, where Microchip failed to provide beyond-expectation support. By contrast, every other company has failed me in significant ways from time to time. Where it mattered and where it cost me substantially in either time or money or both. (And Atmel more than most, by the way. Now that Microchip has bought Atmel, I'm considering using them once again. Maybe.)
There are good reasons to choose other companies. For example, you cannot find a good 16-bit ADC capable of 1 million samples per second, built into a microcontroller, other than with the SiLabs C8051F061. Not in a 32-bit CPU, not in a 16-bit CPU, just in that 8-bit thing (which includes a much-needed DMA unit.) For example, you cannot find a better clocking and timing system than the TI MSP430 B7 timer, nor a better low powered device than TI's MSP430. Microchip's so-called nanowatt devices are a pathetic far-cry, by comparison.
But when it comes to support; supporting their buyers and supporting their tools and supporting their parts.... as a matter of business relationships?? It's Microchip 100%.
