Britain will come to a halt at 4.15pm this Saturday as 40 runners take part in what is arguably the world's most famous horse race. If you can't get to Aintree to see the race in person then have no fear, because betting on the event gets easier year after year. What doesn't get any easier is picking a winner. Can last year's champion numbersix valverde triumph again, will Hedgehunter return to glory or will we have a new winner? Don't ask us.