Gen 1-4 are very guilty of spamming common pokemon on all their LAND routes.
Gen 1- Pidgey and Rattata lines Gen 2- Same, but only gets really bad in the night when rattata becomes ubiquitous. Gen 3- Zigzagoon. Found on pretty much all land routes except Mt. Chimney area, and it doesn't help that they're very common too. Gen 4- Starly Lines and Bidoof lines, especially the latter. At least the Starly line is tolerable for being good pokemon. And there's also Geodude too...
Gen 5 actually isn't so bad. The game throws lots of Patrats at you near the starting routes, then they disappear. You only find Watchog in one area of the main game.
I hope this generation doesn't spam their starter bird/mammal all over the place like the first 4.
Off topic(?) but I don't mind if they release less pokemon if they're quality pokemon. There are only so many cute pokemon you can make before they become redundant.
True that... we don't want more "uselss gimmick" pokemon. I'm also quite sad that all the Pikaclones these days don't evolve (Plusle/Minun/Pachirisu/Emolga). They could definitely be a lot better if they had an evolution.