I have really high hopes for these games (although I would of preferred a R/S/E remake). I haven't been a large fan of the more recent games (Gen 4 and 5, except HG/SS) mainly due to the fact they are starting to lose fun, probably because of me growing older. I'm not being a fanboy of the earlier generations, as I have likes and dislikes for each generation.
Gen 1: For it's time it's hard to make any complaints, except for the creativity of some of the pokemon. My main dislike with these games is the after game. There is next to nothing to do which really disappoints me.
Gen 2: I would say it's pretty similair as Gen 1 but with most of the errors fixed. I love how they used the same Pokemon League. My biggest hate in this game is probably everyones biggest dislike. MILTANK!! God that thing was a pain. I think overall though Gen 2 came out with some pretty good pokemon (Heracross, Scizor, Umbreon, Espeon etc.).
Gen 3: These were my most memorable games to date. I think the storyline improved a bit and the new features worked well. I think the gyms were at a good difficulty (not too easy, not too hard) and the fact they had 2 Pseudo-Legendaries instead of just 1. They also had a lot of Legendaries in this game (Kyogre, Groudon, Rayquaza, Latias, Latios, Regice, Registeel, Regirock, Jirachi, Deoxys and bringing Mew, Ho-Oh and Lugia back). My main downside would be replacing Steven as champion for Wallace. Steven was so awesome, at least they kept him in the game.
Gen 4: I loved the major graphics update and the new feel to the game. I think this was more of a new player friendly game but I still enjoyed it. The thing I love the most is the up grade in Multiplayer. I loved making underground bases with my cousins and trying to ninja each others flags. I also loved the Silver and Gold remake! They bring back childhood memories with the whole new concept to the game.
Gen 5: I have mixed feelings for this gen. I honestly disliked Black and White, but I liked Black 2 and White 2. Although B2 and W2 had some mind boggling ideas (Pokemon Fusion, wtf) I think they pulled a sequel of the first game off pretty well. Starting in a newly discovered area in the same region was pretty cool in my eyes. I also thought a really good thing is having a ton of Magnemite near the Poison gym to make it easier for those who didn't know how to conquer poison types. With the addition of new places in the storyline (Sewers FTW) they also had some cool ideas for the after game and Multiplayer. I found it fun to be able to do the White Tree Hollow challenge (don't know the Black equivalent) and to challenge your old rival from the first (Cheren) and to receive your pokemon from Bianca at the start of the 2nd.