I liked Gen 4, though the battles were kinda slow. The remake looks like it could be neat, but I would have preferred the ORAS art style over the chibi designs.
I've always felt like Johto was the best designed region, though pretty much everything before Unova is pretty good. Unova is pretty much just a giant donut, and it's the start of the trend of the games feeling way more linear in their main story progression. Even if before you did generally progress the same way every playthrough, there were sometimes opportunities to do gyms out of order.
I will give Gen 5 some credit though, it's got some great Pokemon designs and my favorite art style.