Concrete!
I think the best thing would be to invest in anti deer fencing and anti rabbit fencing, expensive but just about everything will get nibbled.

I'm having the same problems with my new garden. I fenced a part against rabbits - so far, so good, but growing things outside it is proving more difficult.

You could look for poisonous plants - monkshood and aconites, for instance. Nandina, daffodils and fuchsias seem immune, and my hebes aren't being eaten - yet!
You could experiment with some "disposable" plants. Anyone who has buddlea or leycesteria will have self sown seedlings that you could beg from them to try out & see if they get eaten.

You'll find lists on the internet of plants that someone thinks are not appetising to these pests, but I've found that the rabbits and deer haven't read them.

The only way is fencing and it is not cheap. Friends just bought a house where there is a large deer population... fencing has cost them several thousand pounds - it is worth it to them and would be to us.

One word: Paeonies.
Nothing will touch them.
Tree Paeonies will give all of the shrubby substance of the Roses coupled with flowers of equal or greater merit and substantially more impressive foliage. They are also utterly bone hardy and virtually disease free, another major plus point over Roses. An entire bed devoted to a selection of them would be simply spectacular.

That is true Ilex!

You could also try
http://buzzorganics.co.uk/index.php?main_page=product_info&cPath=33&products_id=337

We're trialing Garlic Barrier to keep the 'bad' insects off our veg. this year.