I am doing a reassessment on my previous post.
Blastoise and Swampert
Blastoise has rapid spin and hydro cannon. However Swampert's typing makes it impervious to electric types, which was always a plus for me. Blastoise was always bulky, but Swampert takes the cake on this with its typing.
Sceptile and Venusaur
Sceptile was a boss. Sceptile still is a boss. I am going to be picking Treeko once I pick up Alpha Sapphire. However Venusaur learning Giga Drain, having bulk and overall having better typing Poison/Grass especially in this new generation where the fairy type has been introduced, downgrades Sceptile a lot. As of Generation V, Sceptile has yet to learn Leech Seed, Solar Beam or Petal Dance. Thats a shame and I understand he is awesome and TMs are reusable now so he can learn Solarbeam and breeding blah blah blah, however thats a little ridiculous. But after ripping on Sceptile for most of my analysis for these two Pokemon, its about a tie for both of them. Sceptile is really useful in a region with a lot of water. Also Sceptile can take on Roxanne, Wattson, and Wallace/Juan very easily. And if you are going up against Team Aqua then you are really getting it easy. Venusaur also is very useful in its region as well. Venusaur can storm through the first three gyms with the snap of a finger, depending on what game your playing Venusaur can also take on Giovanni very easily (Gen III). If your starter has learned poison moves yet, it can destroy Erika as well. The only gyms that really give Venusaur problems are Blaine's gym and Sabrina's gym, however they are so late in the game that if you played smart you would have types to cover your Venusaur.
So its a tie, both are very useful.
Blaziken and Charizard
Charizard is weak to Rock, Electricity and Water while Blaziken is weak to Flying, Rock, Ground, Water, and Psychic. Those are a lot of weaknesses for two very loved Pokemon. I love both Charizard and Blaziken. They both have served me well in past games. However, Charizard could fly throughout Kanto and its flamethrower took down most enemies. As fun as Blaziken was to use... Charizard was always a step ahead. Charizard has less weaknesses, can fly, and can take on most of the elite four. Hah, for two pokemon that were very disadvantaged in both of their regions its ironic how they come out the strongest. Depending on how you use them, both are amazing. This one goes to Charizard though because;
1. Charizard isn't taking on a region full of water trainers
2. Charizard has less weaknesses
3. Charizard was much much more useful to me at the end of the game. Blaziken had some trouble in the Elite 4.
Now if we are talking about fights here well here goes:
Charizard vs Blaziken: Anything could happen here because Charizard has flying moves but Blaziken has some rock moves. However I think Charizard would easily aerial ace him in one second and it would be over. I mean Charizard has higher base speed for a reason amirite?
Blastoise vs Swampert: This would be a weird battle. So I am going to call it a tie because honestly both of them can fight.
Venusaur vs Sceptile: Anyone saying Sceptile even has a chance. Is lying to themselves. Seriously. I shouldn't even have to explain why Sceptile would be dead here.