1. a set of markers
2. a good pencil case
This is the sturdy long-lasting version. Plus, you can't go wrong with Derwent: this will fit most of your drawing utensils and keep them protected. It's is cheap, thoughtful, and you could add a little bonus (filling it up with brand new toys, for example!)
Price: around $15
3. MORE SPACE
They have a table tops and legs combination with lots of options and prices.
4. a second monitor (or one huge widescreen monitor!)
If your beloved one uses any graphic software (Adobe, Autodesk, Corel, etc...) he/she is probably struggling with the workspace. A second monitor (even a cheap one) is always a source of happiness and helps with the multitasking. Specially if you want to watch your favourite series while you work :) If you are not a two monitor person, a huge one will do.
Price: from $50 to infinity and beyond.
5. a beautiful drawing tablet
If one is already owned, they will appreciate one newer and better. If it is not owned, it is surely desired. Check out the Wacom website so you can choose the best for your budget. There are other brands, even some new chinese cheaper brands, but in this case I am a Wacom fan and the alternatives are not that much cheaper, so my recommendation is to stick to the brand.
Price: from $40 (the basic Bamboo tablet) to $2000 (the awesome Cintiq that allows you to draw directly in it). The Intuos is a good option, not as basic as the Bamboo, very gorgeous, around $100 depending on the version you get.
6. this amazing anatomy book
A different concept, a compilation of over 100 modern artists presenting their personal styles for the human body. Featuring people like Kim Jung Gi, Joe Mad, Loish, and Justin Rodriguez.
Price: $60 if you are in USA, to $100 rest of the world
7. A personal project for a rainy sunday
They are adorable. They are cheap. They are fun. They are unisex. It's the perfect gift for that restless creative mind that just doesn't want to start working right away. It's a DIY blank vinyl toy that allows you to create your own toon. I got one and it was so much fun! You can complement this gift with a nice set of acrylics to get them started. It's called Munny, from Kidrobot. There are different shapes and sizes, and you could buy them already painted if you want.
Price: $15 for the usual (smaller) size.
8. a couple of great graphic design or illustration courses
We never stop learning. You can find a lot of things on the web, and sometimes you can even find something quite useful. A couple of courses, or even better, a subscription for learning in Tuts+ is a great way to say to that meaningful half: "I want you to be better so I can work less".
Price: $15 for each course
9. a cool artist backpack
Of course, you need to be a pro to carry this around. It fits a 17" laptop and a Wacom pad, and it's the perfect gift for the urban digital artist.
Price: $90 (it doesn't include the laptop or the Wacom)
If you want to marry an artist, this could be your wedding ring. I bet that this artist won't even care about your age or gender. This is the jubilee cabinet created by Faber-Castell on their 250 years anniversary. It's pure awesomeness, it has pencils, watercolour pencils, pastels, pastel pencils, drawing pencils, brushes, etc. "The better your tools, the better your work" someone says. In this case, it must be true.
Of course that there are cheaper options, with lower quality and smaller amount of components, aimed specially to beginners and explorers. For example:
Royal & Langnickel have very nice products, nice quality and finish.