I despise Sinnoh with a passion, and prefer Kanto and Hoenn over the other regions, but overall I prefer the newer games. Red and Blue look epic through my rose-tinted glasses, just like thinking about GSC fills me with happy memories, but I'm afraid they can't stand up to the newer games objectively. Ruby, Sapphire and Emerald were darn good with all their sidequests and the innovative region, but there wasn't really that much to do after the E4 were beaten. Emerald had the best Battle Frontier, but the centralization of the Contests meant that you didn't have as much incentive to travel as you had in Ruby/Sapphire (where almost every town had a reason to return to it several times).
The recent games have this mind-boggling diversity to them, tons of available Pokémon and strong trainers to set them up against, challenging battle facilities, a tidy PC system and great battle mechanics. Unova and Sinnoh are pretty bad map-wise (Unova offers no choice of paths, where in Sinnoh Mt. Coronet gets in the way of everything, forcing you to fly between relevant postgame locations instead of actually revisiting places), but the contents of those maps are way too fun to be ignored.
I agree with the crowd saying that we miss certain features that RSE introduced but was later dropped. Simple contests, SECRET BASES (in all caps because they f-ing deserve that), bright colours, the Trick House and the best Battle Frontier ever (or second worst, depending on your point of view) all those made RSE very enjoyable, but there are some flaws to them as well that were fixed later on. For instance, training your Pokémon is somewhat of a chore in those games. The Elite Four's strongest Pokémon is lvl. 58, and there are no rebattleable trainers whose Pokémon's levels exceed 45. The rebattle system is also somewhat unreliable. This was before the physical/special split, so STAB was only a boon for Pokémon whose strongest offensive stat corresponded to its type (Hi, Crawdaunt!).
In comparison, BW2 has it all. Tons of things to do post-game, and they are fairly spread out across the map (Pokéstar studios, the PWT, Join Avenue...). The battle mechanics are as great as ever. There are plenty of exciting places to go. Rebattleable trainers for grinding. The (albeit, linear) region is filled with memorable places. Dynamic music (oh, Accumula Town! Oh, Village Bridge!). Attention to detail make seemingly uninteresting places look so much nicer. They have even made a few attempts at proper architecture. Game-wise, the newer games take home most of the medals. They don't have Secret Bases, they don't have walking Pokémon, and the region is a little too linear to my taste, but the games are still excellent. I have high hopes for the sixth generation, and for generations to come.