- Weapon: Null-Ray Rifle
I've only used Tamiya's stuff before, but it's pretty decent. You'll need to undercoat with gloss black for a shinier finish. IIRC, you can't spray any clear coats over it. Future Floor Polish aka Pledge might be inert enough, though I haven't tried it myself.
One other brand I've tried is from Thailand called TOA. It's pretty durable even without a clear coa, although the finish is more like movieverse Optimus' thigh parts rather than a mirror-like sheen.
Thing is, you can never get a true chrome finish with paint. If you want something that looks like actual chrome, you'll have to use metalizers like Alclad. FYI, you'll need an airbrush to apply metalizers as they won't work when hand-painted. They're also fairly toxic, so be sure to either paint outdoors, or use a spraybooth. Or better yet, wear a respirator.