What house plants will survive on a window sill above a radiator (cactuses apart)?

[Aridane]

Or should I just stick to robust cactuses?

Sansevieria (sometimes known as Mother-in-Law's Tongue!) will be happy. They're quite tough like cacti but a bit different in shape. If you don't mind watering them a lot, pelargoniums (used to be called geraniums) will be good and may well flower on and off all year.

Ah - I already have a rather splendid MIL's Tongue in the same room, thriving happily in neglect (occasionally dusted!). I guess I could always get a mini DIL Tongue to accompany it!

< goes off to google pelargonium >

Aloe Vera love a windowsill above a radiator and don't need much attention!

Agree with others about succulents, and pelargoniums (you probably know them as geraniums, the ones used for summer bedding).

Pelargoniums won't much like a draught if you open the window when it is really cold though.

Ooh - regular geraniums can live indoors??

Yes, they can, if you keep them moderately watered, and snip off dead flowers. My lovely MIL used to have about 25, all carefully tended throughout the year.

Money plant

Ah - but the geranium bedding plants not currently available...

You had me all excited at the idea of something surviving above a radiator and being in bloom!