Wrecky

http://bulbapedia.bulbagarden.net/wiki/Lightning_Rod
Electrike might be worth it, as it gives him protection from electric attacks and lets it get a special attack boost when it switches into one.

But Spheal Sounds fun!

Make sure it's a female goldeen!
Edit: Scratch that - I just checked smogon... and apparently Lightingrod is the Dreamworld ability... :(

http://www.smogon.com/dp/pokemon/seaking

Maybe Burmy? There's several different forms you could train w/ that...

In addition, maybe do:
Armaldo
cherrim
Clamperl
Seel
Spheel
Unown (You're almost assured to get LOTS of offers for this, of course you can't breed it so much as RNG it... if you do several different letters it'd be cool.).

No word on japanese RNGing yet, no. I think we won't have any serious progress until at least the new year...

If you forced me to choose now, besides Goldeen I'd guess Paras and Senret - the two are popular enough to trade easily, but are both obscure enough that everyone doesn't have them. Keep in mind GV gigadrain when training paras.

In fact, one trick is to go over to "uncharted teratory" subforum and look for G4 and before Pokemon who have a thread. If they have a thread because of a dreamworld ability - don't breed them. But if they have a thread do to a new G5 move they can be tutored, Tmed, or heartscaled... look and see if you can breed it on G4 w/ certain moves (such as moves it doesn't learn on G5, thanks to HG/SS's awesome tutors) and see if you can get a combination that'd work awesomely.

But in all honesty, a Paras and Lightningrod Goldeen/Seaking sound just interesting enough to try out... and I haven't seen them in many trade threads. :P

Good luck!

NO! Don't do it!!!!
B/W dream world Typhlosion gets an awesome, and useful, ability! He legitimately obsoletes EVERY Generation IV Cyndaquil/Typhlosion out there!
(As a side note, I know I've traded for shiny near-flawless Cybdaquils in the past - you should be able to trade for one easy if you want a G4 one...).

Breed something unique that'll bring in the trade-requests!

For example, you can breed a near-flawless Lightingrod Seaking/Goldeen; as in G5 Lightingrod prevents electric damage and has a bonus, so it's USEFUL now!

Other than that, maybe do something in the UU or NU tiers... :P Burmy, Donphan, Seel, etc - collectors are going to need near-flawless, shiny versions of these, and they'll trade you shiny OU guys that are in circulation in exchange. WORK THE SYSTEM! :P

(I'm not trying to depress you or anything; I'm just saying focus your energies on what B/W G5 players are going to need, and what you can transfer over to BW when you get it next spring.)

Breeding and RNGing is HARD. You keep producing good stuff, and I'll keep being interested! :P

Wrecky, that sounds good. Will you be free to trade tomorrow afternoon?

Remember that you cannot trade it

ok. lemme clone it real fast

I can give it to you cuz you're my trade partner

You may begin posting

nope.

Sounds good. I'll start the thread as soon as mine gets closed

EDIT: I'll start now

Any names for the thread? Zack is on board as well

I've VMed zack as well, so we might have a 3-man thread

I'll partner up with you. Do you wanna start the thread or should I?

he bro when can we finish our trade?

ok when i see you on bro:D

when are u available to trade?

ok thank so much bro i really appreciate it:D

Ok. i got the guys from supe. i can trade around 8 tonight.

Hey bro can I use my credits in the Shiny vaporeon, Shiny cresselia, Shiny charizard, and the ditto?

ArneXP's the original breeder and on his thread it says "all my pkmn are redis." but im sure he'd appreciated if you gave him credit for his work :)

i am online now can u clone