I have an Asus. I love it.
A number of reviews put the Asus T300 on top. I got one with the keyboard attachment for under $500 last year.
The keyboard has its own power supply so I get 10+ hours of battery life on a single charge.
The only flaw is that the spring (or whatever) on the clamshell is strong, and a few people have cracked their screen opening it. Just have to be careful with it and it will be ok.
I also got my son a Google Nexus tablet. He doesn’t go anywhere without it now.