What is the best PC till date?

It depends on your requirement, how much data you have to process, how large files and programs you want to install on your PC. For a learner your basic needs would be 1gb RAM, dual core processor, 250gb HD.

Apple

These days you will found many of them not single. You can always choose good pc by choosing configuration as per your requirement. so unless you don't mentioned your work it is hard to tell. But good processor like i3, with ram of 3gb and 520gb hard disk should be okay for anyone.

Your question is not clear, it must be what is the best processor till date!,

I hope You have heard of Mac,

Apple Mac technology has an Intel inside, 8 Core Intel Processor on Mac Pro (and can accomodate 32Gb of RAM memory). NVidia or ATI. OLED Displays. integrated Bluetooth and wireless connections is the best till now.And there isanother one called quad extreme or due extreme or probably both are available in market.

core quad is the fastest. the extreme cpus have little less clock speed but they offer other great power to better multi-threading, etc.

And in the coming days intel is making a 7 core processor for home users i think that will be best processor AND it will more powerful than Quad core.

X6800 with EVGA andVIDIA 680i based motherboard & 2 8800 GTX with SLI ready 1KWatt PSU (or 2KWatt) & coupled with raptors  is the best in performance & also
saving electricity!

Regards,
sajee

Now a days you can find good companies in the desktops you can go for lenovo, hp etc.

Apple Macbook is best

It depends on your needs and end usage. I suggest HP.