I would do the horizontal to mimic the subway tile. But only in the top 12 inches.

Oh that's just a sample picture. I'm going to ikea this weekend to buy - that's why I haven't decided yet. But thanks!

I hope you have researched the IKEA cabinet specs. They look great cosmetically but their specs show that they an inferior product. Buyer beware

I have yes thanks. All I want to decide right now is horizontal or vertical.

Horizontal = Contemporary! Deciding if a Contemporary Kitchen is right for
you? Here is a great article: Contemporary
in the Suburbs

For a wet bar area, I'd do the horizontal cabinets. For the detractors, years ago I had IKEA cabinets and through the years I've had many other IKEA products. They've actually stood up quite well. You just have to pick properly.

vertical all the way. Just my preference, no facts or arguments to back it up ;)

Thank you! I also prefer the vertical simply because I think it's easier to open and seems to hold more stuff (that's probably not true since dimensions the same). But yeah horizontal looks so much sleeker and modern :)

Ikea cabinets have a 25 year warranty.

That's true, but their warranty is very limiting. For example, the warranty does not cover a knob/handle falling off or wall shelves. But of course, everyone has their own preference. A company that truly believes in their products should offer a life-time warranty. Solid Wood Cabinet Company Warranty vs Ikea Warranty (just search for the kitchens section)