Weil is a good choice. If you have nothing but a general interest in commercial law Weil/Cleary have the broadest practices and most solid training programmes. Cleary heavier on competition, litigation and public M&A, Weil on finance, restructuring and PE. Weil arguably a bit more prestigious in London but has been a bit lacklustre recently tbh: Michael Francies is retiring, it lost its Band 1 PE ranking, no notable recent mandates, partner losses in the US etc.
If you want to do top-shelf high-end complex M&A and finance
Davis Polk is very good. Its US practice is popping off, and despite being tiny in London it packs a punch. Lateral opportunities arguably better than Weil/Cleary.
S&C is a bit crap in London (respectfully).