I've been on dedicated servers for a little over 5 years. In my experience the only crashes have occurred when I made a mistake, and they were easily resolved by fixing the (my) software and rebooting the server myself :)

I doubt this is your problem, as good hosts will point out within seconds that it is something you did to cause the crash!

Hardware does sometimes break, with my host it has happened only once in 5 years across several servers. They spotted it before me, phoned me when it happened, and had it almost fixed at that time......it was about an hour before the replacement hard drive was up, restored, and running as usual.

Apart from a slight decline in revenue the hardware issue would have probably been totally resolved by them without me ever noticing ;)

Now, here is the cruncher! There are many types of dedicated host! Some just provide the hardware and look to you to deal with everything else, some provide limited support, but, you still need to be very technical, and some take on the job of looking after you all the way, even when you show yourself to be an incompetent idiot in a particular field of web hosting.

I like the latter, I like those that want to be the experts and get it right!

It is of course not the cheap solution when you look at the monthly bill, but, it is the very cheap solution when you look at the monthly profit Vs the cost of supplying the expertise to do that job!

My recommendation without mentioning names here (as it is against the TOS) is to go with a totally, fanatically based support solution to dedicated hosting. Not a cheap solution, but, one that will out perform your requirements :)