Pretty sure this topic hasn't been made in ages, so it's all good ^^
I usually call my ideal team my "dream team", and I certainly do have one. It's a team that's basically been on my mind since 2nd gen and has slowly developed over the years to include extra members. There's a reason for every choice beyond simply "my favourites" (because lord knows I have tons of favourite Pokemon), and I did try to model it after a proper team with type coverage. Things got a bit sketchy once gen 4 was released, though...
Bulbasaur: For some reason, I can't picture this team without viewing Bulbasaur as my starter. Maybe it's because it's the first Pokemon I ever had in-game (that's always stayed with me), but it was also my main character's starter in my first ever lengthy fanfic. When I think about which of the current 16 existing starters best suits myself, it's always Bulbasaur by a mile. It's just one real special Pokemon for me.
Raichu: I think for anyone who knows me this one's a no brainer, but in my mind it goes deeper than that. Raichu is both my favourite Pokemon and one of the Pokemon I could truly see myself training. It's a rodent, it's fast, it's spunky, and it's adorable. Being a bipedal Pokemon of its height, it would be easy traveling around with one, and there'd be lots of different ways to battle. However, I wouldn't mind starting out with a Pichu and working up to Raichu. More bonding time that way ^^
Charizard: While Bulbasaur is the first stage starter I always view myself with, Charizard is the final stage starter who's been a stable member of my dream team since the start. A bit of it is Anime influence, but the rest is just the creature's pure awesomeness. It's a fire dragon, it's rather large, and it can fly. I crave that in a Pokemon team. The fiery personality of a Charizard is also something I see fitting with a part of myself, and I'd certainly be up for the challenge of raising one.
Snorlax: I first bred and raised a Snorlax in gen 2, and the thing has been a stable member of my team ever since. I love that Pokemon for everything it is. Huge in size, powerful, able to learn a wide variety of attacks, laid back, and cuddly. Sometimes you just gotta sit back and relax, and no Pokemon does it better than a Snorlax. I can easily picture myself resting against one, or when it's actually awake - riding on its shoulder. Food would be a problem, but that'd just make things more fun. We'd have epic pizza battles.
Vaporeon: This is probably the strangest member of my team. There are lots of Water-type Pokemon, but I've always been drawn to the ones able to walk on land. In first gen, we had very few that fell into that category but still a fair amount... and my mind always turned to Vaporeon. Its power and grace; the ability to run on all fours freely and live on land just as easily as in the water; the fact that it's a canine-ish creature (I see it as a fox-thing moreso than a cat). All of those reasons and more are why Vaporeon has always been my Water-type of choice for that team. It was also the first Water-type I ever trained, and that's probably stuck with me a bit just as the Bulbasaur thing has.
Steelix: From Onix to Steelix, I can see myself with this Pokemon solely for its typing and its size. I adore huge creatures, whether they be historic (dinosaurs w00t) or make-believe. I'm just drawn to the things. Onix was and still is one of the largest Pokemon around, and it's part Ground-type - a type I used to obsess over in gen 1 & 2. I could see one being the hardest Pokemon to tame initially, but they strike me as very proud, respectful and loyal creatures. I often imagine riding on the head of one and staring off into the distance... it'd be so awesome. As for Steelix, it'd only be natural that I'd one day evolve the Onix (if it wanted to XD).
Heracross: My bug-type of choice! As awesome as Scyther is, Heracross is it for my ideal team… Probably because it shares two of my favourite types these days (Bug/Fighting. One of the best combos for me ever). There's also the fact that it's a beetle, and I freakin' love beetles in general. I could see my Heracross being a powerful physical attacker, while my next Fighting-type (and final team member) would focus more on Special based attacks…
Lucario: Oh yes. Fangirl moment here, but for me it also fits very well. Lucario is part fighting-type (again, one of my top favourite types nowadays) and is also an aura user… For that reason, I could see one being the deepest Pokemon I'd ever train. To properly sync with a Lucario, you'd probably have to attempt to tap into the aura yourself - or at the very least learn to understand it. Growing alongside a Riolu or Lucario would be a very fulfilling experience I'd think, and one I'd love to share. It'd also be really fun to spar with one ^^
Lolz novel post. But there you have it.
There are a number of Pokemon that could easily be on my ideal team but aren't due to others beating ‘em out type-wise: Arcanine, Zangoose, Flygon, Pidgeot, Torterra. All of them are special to me for various reasons, and I could easily see myself training them. Maybe as a second team? If so, my Water-type would probably be a Buizel, Squirtle, or Lapras.