Now that we have a release date of 3/6 and even knowledge of when the gerbils and Celebi are being released (and those events have already leaked), a lot of people are going to have to make the decision on what version to buy.
Not to be racist, but I'm going with White on this one because I value White Forest and it making sure I have to do less Pokeshifting than I would with Black. Wanna know why? Here's the list.
But I had to resort to deciding based on the additional Pokemon, because looking at the version exclusives in this gen didn't help one bit.
Note: Monmen/Churine (the Grass-types) are not version exclusive as they can be ingame traded for each other in the respective versions.
Stat wise, White gets the advantage on Special Attack (105 in the first form? Yowza) and HP, but Black's have the advantage on speed although neither one is fast by any means. The kicker is the ability advantage - there are way more situations where Magic Guard or even Dustproof will come in handy than Frisk ever will.
White: Washibon/Wargle (Normal/)
Black: Baruchai/Barujiana (Dark/)
Oooh, a Dark type. Except the only thing that kept Wargle Low in the tier list was the location and late evo - Wargle especially is absolutely amazing post-National as it can actually do damage. Baruchai's offensive stats, as previously mentioned, are TERR-IBLE.
Flying type Legendary Genies
White: Voltolos (Electric/)
Black: Tornolos (no dual type)
Both having identical stats means it comes down to typing and movepool - and Voltolos having the advantage of STAB Thunderbolt out of the box when you get it + just enough Special moves to be usable gives it the win.
Version Mascot Dragons
White: Zekrom (Electric/)
Black: Reshiram (Fire/)
These things were designed to be perfectly identical to each other, and it works out pretty well. I do have to give the edge to Reshiram since it can super-effect the only thing that resists its other STAB - although quite frankly, 100 power off a base 150 Attack stat is going to KO whatever hits it anyway.
Slight advantage: Black
White: Caterpie/Metapod/Butterfree (/Flying)
Black: Weedle/Kakuna/Beedrill (/Poison)
Butterfree still has Compoundeyes, right? And a 98% Sleep Powder? OK, just checking.
2nd Gen Debuting Dusk Stone users
White: Misdreavus/Mismagius (Ghost)
Black: Murkrow/Honchkrow (Dark/Flying)
Ah, a usable Dark/Flying. Mismagius is a decent Special-attacking Ghost, and obviously Black wins the 1v1, but this one really comes down to preference.
Black: Houndour/Houndoom (/Fire)
Both of these final forms have base 90 Attack, but Houndoom has 110 SA and a second usable STAB. This one isn't even close.
Mushroom-based Spore users
White: Paras/Parasect (Bug/Grass)
Black: Shroomish/Breloom (Bug/Fighting)
Again, not even close. Breloom has 100+ base stats (or close to it) on Parasect, just enough Speed to be dangerous, and STAB Fighting is pretty good in this game in case you forgot.
Differently-charged Pichu ripoffs
Nobody cares either way. Next.
Gender-exclusive 3rd gen bugs
This didn't get a lot of press yet - but the existence of 3-stage boosting moves in this generation swings this. Namely, the fact that Tail Glow is now +3 to SA. Granted, it doesn't do much for Volbeat's 47 SA, but at least it's a gimmick. Illumise has... Flatter. Yeah, I'll take Volbeat.
Pre-National: White 3, Black 1
Post-National: White 1, Black 3, 2 draws
Total: 4-4-2 (push)
So yeah, unlike last time when Heart Gold was the clear winner (and idiots bought more Soul Silver anyway), there's no clear winner on the version exclusives in this game. Granted, you'll see more of the pre-National ones, but Black roars back to make it an even fight in the end. Also, Plusle and Minum can go take a flying leap.