I have rented my house for a year now and the landlord never gave me the right key to the house which he was informed of... this wasn't a problem as I used the garage door opener to enter my house and I always kept my doors locked.

Well a month and a half ago my garage door motor burnt out and I informed my landlord of the problem and that I had no key and couldn't lock my house up...

a month goes by and my house gets robbed, can I hold my landlord resposible for the monetary value of the items stolen since they wouldn't have gained entry if my house was locked and he did not give me a key or repair the garage door opener in time?

They "walked" into my neighbors house as well... and didn't force any entry into anyone else's house.

conveniently I get a key and the garage gets fixed a week later...

I'm sure a lawyer would take the case, but you should never have moved in without a key to the front door, you should have refused to pay the rent (properly, through a lawyer by having the funds held by a third party) and taken care of this asap.

How did you lock up when you left? I wouldn't trust a garage door as my only way of securing the home.

Yes the garage door was the only means of securing my house... I just used the garage door opener and left the entrance to the house unlocked from inside the garage...

You should have taken care of the door lock a long time ago. Just using the garage door as your entry to the home was not a great idea. Many homeowners carelessly do this and burglars are hoping that people with garages do this sort of thing. I doubt if you would win in court as a new lock for a door is quite inexpensive regardless of who buys it - you or the landlord.