Seatbelts in cars - Legitimate or nanny state - Nanny State
Helmets for motor bikes - Legitimate or nanny state - Nanny State
I'd take away those obligations as long as the 'non-user' paid extra insurance. I don't want to pay the extra health care costs for someone's stupidity when they suffer worse injuries than necessary.
Make some dangerous drugs illegal but not others - Legitimate or nanny state - Depends upon the wider effects to the community, not just the user.
Decriminalising currently illegal drugs isn't going to increase the number of drug users, if people want to use drugs they can get them now easily enough. The illegal status only criminalises hundreds of millions of people in the world, makes drug dealers very rich, and diverts police and courts away from real crime. It would reduce the need for addicts to commit crime to pay for their drugs, assuming that they would be cheaper if suppliers didn't have to go to such lengths to import them, or bribe law enforcement and customs services in that process. Plus drugs wouldn't be adulterated by poisonous substances so dealers can increase their profits.
All in all, decriminalisation would have beneficial effects on users and the community.