Both (SSD & HDD) should last for at least 5 years.
On HDDs while capacity has gone up I find that their reliability has gone down.
1) Use newegg, even if you do not buy, to evaluate what is more reliable.
2) even if you go the route of an SSD, you would need a HDD as SSDs over about 120/128 gigs get expensive.
If you have gone thru 3 HDDs in 2 years I would look at an underlining cause such as a PSU or MB causing the drive to fail. You did not list the specific model of WD drive.
EX:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007603%2050001306%20600003269%20600003298&IsNodeId=1&name=1TB
As you can see WD 1 TB drives do not have what I call a good rating, for ex:
.. Geen Drive .. 26 % 1/2 egg ratings
.. Blue Drive .... 43 % 1/2 egg ratings - OUCH
.. Black Drive ... 19 % 1/2 egg ratings
.. Samsung F3 .. 14% 1/2 egg ratings (HDD that I normally buy)
Ref for WD drives:
http://www.newegg.com/Product/Product.aspx?Item=N82E16822152185&SortField=0&SummaryType=0&PageSize=10&SelectedRating=-1&VideoOnlyMark=False&IsFeedbackTab=true#scrollFullInfo
For Samsung 128 gig 830: 1/2 egg rating 9 %, beats most HDDs
For Curcial 128 Gig M4 - 1/2 egg ratings 6 % Great
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148442&SortField=0&SummaryType=0&PageSize=10&SelectedRating=-1&VideoOnlyMark=False&IsFeedbackTab=true#scrollFullInfo
http://www.newegg.com/Product/Product.aspx?Item=N82E16820147134&SortField=0&SummaryType=0&PageSize=10&SelectedRating=-1&VideoOnlyMark=False&IsFeedbackTab=true#scrollFullInfo