I never really liked the 500 series - I preferred the 1400 (I know, weirdo). The Intel MacBooks have had their moments (glass trackpads, SD card readers, quad core in the 2011 15"), but almost all of them had design defects of some kind:

* Original white and black MacBooks had sharp edges and cracking wrist rests

* 2nd Gen MBP had 8600GT chip death issues

* First Unibody MB/MBP had glossy screen not suitable for indoor lighting

* First Polycarbonate Unibody had chassis cracking and rubber base warping issues (but was otherwise an excellent machine, too bad they didn't resolve those issues and keep selling it...)

* 2011 15" will all eventually fail due to faulty GPUs

* 2012 Retina MBs had underpowered GPUs

* Retina MBPs had soldered RAM and proprietary SSDs (10.13's NVMe support for those older machines with a simple adaptor has made a complete mockery of anyone defending Apple's stupid proprietary pinout, too), glued batteries and display coating problems

In saying that, the original aluminium unibody was a spectacular design. It felt so much more premium than any other machine of the time it was absurd.

I personally think absolute peak Apple notebook was the 2012 MacBook Pro 15" with the Anti-Glare display. All the best things about the pre-retina Unibody design, but serviceable, with USB3, no known serious GPU or CPU flaws, and none of the retina issues such as staingate or glued battery.

Had they made a Haswell revision of that to get the better battery life I'm reasonably convinced it would still be a seriously popular machine today.