A tortoise?? Can live indoors but obviously love the warm weather.. Fairly easy to look after, running costs low.Down sides cost a lot to buy, only a limited amount of interaction possible.
Don't tortoises live for about 200 years? You need to make provision for it in your will, that kind of thing.
This won't sway anyone I don't suppose but...if you're thinking rabbits, think chickens instead. Re-home some ex-battery ones some from www.bhwt.org.uk
(sorry, my usual plug but it is very worthwhile) - just like rabbits but they lay eggs and put themselves to bed.
Cats are the best pet surely - you never really own them, they can express their natural behaviour in a way most other domestic pets can't. I once read 'Dogs have owners, cats have staff' which kind of sums them up I think.