You should post your budget. I think Dell laptops are the best on market atm. Old Thinkpads are great too (especially for the durability).
Please share your experience with laptops as well.
I think Laptop are only good for the portability, and I think desktop PCs are better otherwise (desktop PCs are much easier to upgrade and its easier replace broken parts. And you can get the build/parts you want). If you need a system that you can use to freely test stuff on, I recommend you get a Raspberry Pi (or a clone) or use a virtual machine (like VirtualBox or Qemu).