My buddy builds/sells custom PCs and uses Seagate exclusively because of the 5 yr warr.
He told me he very seldom gets a bad one.
Prior to that he used only Maxtor which he dumped due to high failure rates, then he moved to Seagate.
I bought two Seagate drives within last yr and have had no problems with Seagate.
Newegg rates Seagate highly and that's good enough for me.
Western Digital is an excellent HDD also but only gives a 3 yr warr, so I went with Seagate.
'Lifetimes' of HDDs vary.
They say they last 3-5 yrs but should last longer.
I still have and use a 10 yr old IBM HDD that still runs rock solid but a bit slower since it runs at 5400 RPM.