I caved and purchased a try-me set of sprays from Lindy Stamp Gang, and they are pretty fun. I looovee the look of ink sprayed over a stencil. They're glittery!
These are a step down from standard Windsor&Newton watercolours and will probably last many years. I much much much prefer the dry cakes over the tubes, and it's kind of hard to find them sometimes.
Golden Gel Medium
This is a new friend of mine, and can't wait to play with it some more! Super thick and dries clear, so you can make as much bumpy texture as you want.
Faber Castell Pens
The pens say they are waterproof but I disagree. They run like crazy. Maybe I'm just not using them correctly?
Occasionally I will use some acrylic paints (journaling, mostly), and if I do I prefer Jansen Art as they have the exact colours I want but with consistent pricing. For easy to find colours, I will usually go with Stevenson.