I usually buy Vallejos or Citadel Miniatures and have heard talk that some of the other brands of acrylics have been reformulated to address some of the issues modelers experienced.
Here are my experiences with the following brands of paints. I'm wondering if these issues have been addressed, or at least how best to avoid them. I still have bottles of these paints.
* Tamiya Acrylics: Brush-painting with them could produce a peeling skin when brushed over the first coat. Some painters say add a Clear Flat Base to avoid this.
* Gunze-Sanyo: These have a tendency to dry glossy or semi-glossy. Some painters say add a Clear Dull Base to avoid this.
* Testors Acryl: Either too thick or too thin and the shelf life isn't that great. Very good for airbrushing, not so good for brush painting.