I have a hard time keeping enthusiastic about nearly every series. All of my favourites, at some point, have disappointed me or taken directions away from my general taste. FF is probably the big one for me. I've liked each entry since VII less than the last (with the exception of XII, which I loved). For me the series has four really solid entries (V, VI, VII, XII) with the rest ranging from flawed but enjoyable to outright ugh. Still though, when I think about favourite series, FF definitely pops up first.

Zelda is another one that has a whole pile of fabulous games while the later games, I feel, are a little too easy or implement some elements that I find really obnoxious. Not that Zelda games were ever really hard per se, but the older ones at least challenged me to experiment and figure things out for myself. I can appreciate that I'm nowhere near the demographic of Zelda games anymore, but I can still tell when I'm having fun figuring stuff out and when I'm just doing what the game is outright spelling out for me. Still, I think anyone would be hard-pressed to find a series with as many solid gold games as Zelda.

From more recent stuff, I think it's great how strong the Street Fighter games have been throughout the years. The various editions of II and III are just great games and more recently I've just got a ton of fun from IV.

From Software's Souls games are excellent too. Demon's was really good and now Dark Souls is just one of the best action-adventure RPGs I've played in years. What's great about them, I think, is that they do what DQVIII did a few years ago for JRPGs - they basically take an old formula and bring it to life using modern graphics. DQVIII was like a perfect adaptation of what a lot of kids probably imagined their old NES RPG and adventure games to look like if they got to see it from the perspective of the characters. The Souls games (especially Dark) are like the perfect modern mix of Castlevania's difficulty and monster gallery, Metroid's elaborate inter-connected world design, and the original Zelda's "here's a weapon and some bare-bones plot, now get going".