When staring a new save file on all pokemon video games ,which starter pokemon do you prefer and why?

I almost always go with fire because those tend to be the strongest and coolest looking ones and every now and then I will pick a water starter. Never grass.

Mostly water because I make them my HM slaves and teach them Surf, Dive, Waterfall.. etc.
You get the idea.

I usually go with the water type starter because normally the only good water type pokemon in each region is the starter and since you need a pokemon who can use surf and waterfall in every game I get the water type starter most of the time.

I tend to go with with Grass types. Their power moves tend to be more powerful, and they do have Absorb moves to take HP back when they get low on health. 

I usually go with fire starters for the reasons zander listed.  I typically think they are the best looking, and I enjoy their power.  However, sometimes I will get in the mood to simply be different, and in that case, I'll pick a water starter.  I can only remember of once or twice where I started with a grass Pokemon.  I do enjoy their health absorbing moves, but that's about it.  I'm not really into using moves that cast states, which it seems like a lot of grass Pokemon focus on.

I usually choose the fire type because I have a desperate thirst for power and the fire type Pokémon at my command makes me feel slightly less insignificant in the grand scheme of the universe. Then I remember I'm just playing a video game and ask myself what I'm doing with my life.

I tend to end up with the water Pokémon more often than not. I like their moves most of the time, the stats are usually better than at least the grass starters, and unlike the fire types, which is what two of my favorite starters are, they don't have typing I don't usually like using. Grass Pokémon are just generally too weak, really. Too many weaknesses, usually not many great stab moves, and I don't think they look as good either.

vizzy900 : I pick Water Starters because they learn an important move which is require to beat the game. You know, Surf of course . Water Pokemon can learn powerful moves. Such as Hydro Pump, Waterfall (Required to beat the game in some Gens), Hydro Canon. Grass isn't bad, but it has 5 weaknesses, which is too much for one type. Fire is good, but I find it too overrated. I pick Water Starter in almost every game.

Most of my starter Pokemon is happened to be fire (used in 3 generations [Gen I's Charmander, Gen II's Cyndaquil, & Gen VI's Fennekin]), then follow by Grass (Used in 2 Generations [Gen III's Treecko & Gen V's Snivy) and then Water (Used in 1 Generation [Gen IV's Piplup])

So after this list, I'm mostly a fire starter user in the whole Pokemon series.

Fire.
Okay,mat first, I played Soulsilver. I had no idea what sort of raw power I was getting into.
Of course, that was...5 years ago? Wow. I was 9, and I was picking based on looks, because I had no idea what Pokemon was aside from 4 cards-Charmamder, Charmeleon, Charizard, and Team Magama's Groudon.
But I grabbed him, (his name is Jacob, he's stuck on White right now) and when he evolved at the bell sprout tower I was just like "YES." I still personally think Quilava is the best looking Pokemon in the game, despite the fact that they took away the fire-frill constantly being fanned in battle.
And then I got Typhlosion. This was a wonderful addition for me, his good speed and high-powered attacks let me sweep lance with eruption. He was level...80 or so, granted, but it was fun.
Next game I bought was Platinum. By this time I also had battle revolution, and had grown to like Nate's Monferno, plus my neighbor(named Nathan, coincidentally) had given me about 60 cards, about 7 leading up to Infernape. Love at first sight, and I wasn't a big fan of the other two at the time. (although now I love 'em both) The Close Combat/Flare Blitz/Fire Blast/Aura Shpere combination was gorgeous, and then I was hooked.
Next came White. I wasn't impressed by the starters, and didn't know what their 2nd evolved forms were(had the artwork), so I prayed and grabbed Tepig. He turned out to be a fat boar with a fire beard. Another fire-fighting. I tried to love Big Joe, but I couldn't. He was to fat.
So, I have fire one last chance, and they swapped the common fighting type for my Fenneckin, Gandalf the Red. Psychic-Fire seemed even more devastating than the others, and I loved him too.
Then, for the first time, I chose a water starter in Mudkip. I couldn't stand the thought of a third fire-fighting type.
But Fire does generally seem to be the best, with devastating amounts of power, and in Emboar and Delphox's cases, high defenses/special defenses, respectively.

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