In my opinion, it's understandable that people don't want to argue about shippings. Generally, they're a rather touchy subject, especially for those who are rather ideologically sensitive (for instance, I've seen a lot of het pairings and very few people brave enough to state that they have found a slash/femslash pairing interesting. In fact, has anyone even stated a femslash in here? o_O). Not only that, but we're really hoping that everyone is treated respectfully here and some people (not saying here) have possibly been flamed for liking certain pairings.
That being said, I will go ahead and state my own favorite pairings and the reason why I support them.
Red x Green (male) originalshipping
My OTP, pretty much. XD I pretty much started liking this pairing as soon as I read a oneshot about them. Of course, this is after reading a bunch of oneshots about them and trying to convince myself that shipping in Pokemon = BAD IDEA. However, I eventually fell under the fanfiction writer's spell, and thus, here I am.
What mainly appeals to me about them is mostly the complimentary personalities -- that, and the fact that I really can't imagine them with anyone else. Sorry, but I really don't like the idea of Green x Blue (female), mainly because Blue's personality just doesn't fit him as far as I am concerned. As for Red x Yellow, as much as the pairing does make sense I just can't find myself liking it. Call it a bit ridiculous, but the possibility of Red x Green (in my mind) outweighs that of Red x Yellow.
I never really imagined myself liking this pairing, especially since I dislike Ash x Gary. So to really come to this point is just as much a surprise to myself as it probably is to people who know me well enough. (Especially considering I'm not the biggest fan of slash.) Oh well. Got to this point, staying at this point. XD
Gold x Crystal mangaquestshipping
While Red x Green is a pairing I got hooked on more recently, I have actually been a long time fan of Gold x Crystal. Ever since I heard that Gold and Crystal were in the manga, I started shipping them -- this is because I already ship their game counterparts. When I read more information about their interactions in the actual manga, it only made me like the pairing more, which is why it's high up in my pairing list. It's not necessarily my OTP (Red x Green has stolen that spot!) but it's definitely high up there in the most appealing pairings to me.
Let's see... their personalities match, for one -- or at least what I've read of them. Every interaction that I have seen between them has made me a very, very, very happy CAttkD. <3 Not only that, but Gold takes the full brunt of an attack aimed at both him and Crystal -- seriously, if that's not dedication, I don't know what is.
Ruby x Sapphire franticshipping
Meet my original OTP before Red x Green barged in. They were actually when I first started shipping manga characters in general -- in fact, I liked them even before Gold x Crystal! It's their relationship that got me really into the manga in the first place, and made the Ruby/Sapphire ark among my favorites of the manga. My reason for supporting them? They're practically canon.
They have already confessed; the only thing really left for them to do is to actually get into a relationship (and for Ruby to get over himself and acknowledge that they had had a confession chat in the first place). It really struck a chord in me when Sapphire was the first to confess, and their relationship is really fun to watch unveil and develop. I heard someone else say in here that this is his/her OTP, and seriously, I can't blame him/her. This is a fabulous pairing, and even though it's no longer my OTP, it's definitely up there in my favorites.
Diamond x Platinum/a commonershipping
This is another one of those "I like it because I like the thought of their game counterparts together." I do recognize, however, that there is a significant difference, and I mean significant, between them and their game counterparts, especially in personality. This doesn't make me like it any less, however; in fact, although I don't like Platina too much and Dia's just a cutie, I still think the two of them fit together. Dia's just so sweet to Platina (in canon!), and is rather supportive of her where Pearl is not.
A better way to argue for this pairing is to argue against its competitors, Dia x Pearl and Pearl x Platina. Now, while I am okay with both of those pairings and I don't want to dump on them, I just don't see either of them happening -- in the case of Pearl x Platina, Pearl seems more annoyed at Platina than infatuated with her (and Dia is shown in the very beginning when Platina is introduced to be swayed by her beauty). As for Dia x Pearl, once again, I am not a huge fan of slash pairings in general -- and honestly, I think their relationship is brotherly at most (although I can see where many Dia x Pearl shippers can find their hints, especially when Dia lashes out at Pearl for being treated the way he is by Pearl).
(Please note: Just because I don't think Pearl x Platina is plausible doesn't mean I don't like its game counterpart, Barry x Dawn -- in fact, that used to be one of my favorite pairings.)
I think that's all I have to say as far as my pairings are concerned. I don't bash pairings, so any pairing you throw at me, I may dislike it, but that doesn't mean I hate it intensely or I want it to burn in ashes. I still favorite works that are based off of pairings that I don't necessarily support.