Username: Olli97
Favorite Rival: A bit of a tough decision here. It's tied between Blue and Silver, since they're the only rivals whose ambitions and characteristics are some that I like, as well as being some that are clear in my mind. Obviously due to the amount of playthroughs I've had in the generations they're featured in, compared to the few I've had in most of the other games. Brendan and May were kinda meh. They were essentially just the same character, so choosing between them would be down to designs only, if we had to follow the game canon, and all in all, there wasn't much to them. They were pretty much just trying to fill up their Pokedex in attempt to help their (grandpa or dad, I can't even remember), and occasionally battled you, just to see how far you'd gotten. All in all, they were really forgettable characters who didn't really serve much purpose in the games, which is why they're far from my favourites. That's why I liked Wally much more than those two (whom you btw forgot to add :p), because he actually had goals fitting of a rival, and was kind of an interesting case. But not my favourite either.
I didn't really play DPPt and BW enough to really form much of an opinion on the rivals, but as for the little I have: I liked Barry's personality, and I feel like he was definitely the one who was richest in that department, at least in my judgment. However, due to the fact that I've only really played DPPt about 2-3 times, with very big gaps between, I never really grew to like Barry too much. I mean, I can't even remember his team. As for Bianca and Cheren; I barely even saw them as rivals. I just saw them as the friends whom you started your journey with, and who occasionally battle you, just because that's the point of being Pokemon trainers. There wasn't really any rivalry in it, aside from the catching 'em all part, which has honestly never been any big priority of mine in Pokemon games, so I didn't really care much for it. Personality-wise though, I really like them. While it may be a bit cliché, it definitely fit into a Pokemon game, and adding on to what happened to them with the sequels, it just gets better. We get to see the nervous side of Cheren in B2W2, as the first opponent he faces as a gym leader, something he kinda hid behind a cover of knowledge about everything regarding Pokemon throughout the entirety of BW. And we get to see a more serious Bianca, which I didn't expect. But yeah, kinda going off-topic here! :p
Hugh was just hard to get in on. He was a very mysterious character to me, and while he definitely felt more like a rival than Bianca and Cheren, he just didn't seem to have the attitude of one. He didn't really care as much about you, and had more of the attitude of Bianca and Cheren towards you, while still going with his goal to beat Team Plasma. It just kinda seemed like Hugh was a copy of Silver, and I have still only played through B2 once, so yeah :p Not much to add here. I really like how loyal he is towards his sister though!
But yeah, Silver and Blue. Both probably the most arrogant and cocky rivals. I think the only reason Silver is really tied with Blue, is because of how much I love the games he's featured in, and because I like his goals, and how we're pretty much getting in the way of him, making it more real than with Hugh. His goal to beat Team Rocket, just because he dislike their actions, and because he dislike his father, Giovanni, I guess. And we're just one step ahead of him with beating them all the time. I can understand his anger. But in the end, Blue is really the real definition of a rival. He shared the same goals as you; fill up the Pokedex and become the champion (and that was at a time when catching 'em all was actually possible ;)), and it was just all about who was the fastest. And the rival battles to test how far you'd both gotten. I know new ideas for rivals make it more fun, but it doesn't get any more true than what they did with Blue. And that's why he's my favourite I guess :p
tl;dr: My favourite is Blue :)
Since I can't remember any themes apart from Blue's champion theme, I'm just gonna skip that topic and go to the old one :p
Who is the rival you had the most trouble with?
Oooh, I've had my fair share of trouble with just about every rival, but the one instance I recall the best, was in the battle against May/Brendan on the road to Mauville in R/S/E. I don't know why I always had so much trouble with that battle (probably because I was (and still am) a giant noob at Pokemon ;p), but it always took me forever to get past that battle. Same goes for the one in Lilycove. There aren't really any I can recall with others, except for against Blue in the second Champion battle in FR/LG, but I don't really count those, since they're supposed to be really hard. But May/Brendan are pretty much the first to come to mind, when I think of rival battles I've had trouble with, despite the fact that I hardly even see them as rivals xD Another one was the one against Silver at the end of the Victory Road in G/S/C, but taking a look at his team again after all these years, it wasn't even that hard. Heck, G/S weren't really hard games at all :p