Some hilarious suggestions on here…
Cash ISA: saving not investing, you’ll lose money in real terms
Premium bonds: ditto, plus the govt is laughing at you
Lottery: gambling, not investing
Classic cars: huge cost of ownership
Funding Circle: too much is unknowable, rumour mill not good
Royal Mail: political football, bad unions
Sirius Minerals: rrrrramp-tastic! You cannot be sirius
Crowdfunding = charity, fraud
Bitcoin = daffodils, fraud
Apple: a fashion co. not tech, it stopped innovating years ago
Watches: risk of theft/damage
Red/black, magic beans or Nigeria make as much sense as many of those.
Do this: depending upon your age, choose a SIPP or LISA as your tax-efficient wrapper, then choose whatever Vanguard equity trackers appeal. Only invest in what you understand. Offset mortgage is also a decent shout.