IKEA is like no other company when it comes to scale of economy in their home furnishings. We don't love every single thing that IKEA does, but when it comes to kitchen cabinets, We really didn't see any other way to get the size and style of kitchen we wanted.
IKEA cabinets are completely modular — you can buy them in any configuration and adapt them to your style to a rather astonishing degree, especially if you want a more modern and sleek look. Their cabinets are frameless and easily adaptable to modern, flat-fronted doors.
Some people are suspicious of IKEA cabinets, since they are made of particle board (similar to MDF - medium density fiberboard, but a reader pointed out that IKEA actually uses particle board not MDF in their cabinet bases). The low cost of the cabinets and their material are red flags to some folks who just really want the best for their kitchen.
But here's the thing. Most off-the-rack cabinet systems are also made of some grade of particle board. Any other cabinets we could afford (like the Kraftmaid cabinets or other lines sold at stores like Lowe's and Home Depot) were also particle board. You can go a step up and get cabinet-grade plywood, but there is some debate over whether that is actually superior to particle board or MDF. To go all the way to the top and buy solid wood cabinet boxes, well — that just isn't feasible for most people. It would have cost tens of thousands of dollars, money people couldn't justify even if they had wanted to.
The most key part of a cabinet is the drawer. If anything is going to swell and warp, it's a drawer. But IKEA's drawers are solid metal, with really superb hardware, Blum hinges, and drawer dampers.
Yes, IKEA cabinets are cheap, but that doesn't mean they're shoddy or flimsy.