I would highly recommend Lifeline AGM batteries.  My OEM Marine deep
cycle battery died in only 8 months of use due to vibration; my
Lifeline AGM battery has been in for over 3 years with no problems to
date.  And no maintenance required.

http://www.lifelinebatteries.com

Marty

Hi HT,

For wet or lead acid flooded batteries, the best seem to be made by
Trojan. Before I got the newer three stage charging system, I was
getting 4 1/2 years out of them. With the three stage charging system,
it appears that they might go as much as ten years, Not there yet,
Only been about seven.

For maintenance free, I just installed Deka AGM made by East Penn. A
sealed battery with a reputation for long life. While a bit more
expensive I am hoping that the decreased maintenance will compensate.
Deka seems to be the choice of the higher end coaches.  

If you want real quality, then consider either the Rolls or Surette
but you need a fat wallet for those. They are seldom used in RVs.

George

I see where ht <Munged89Roadtrek@ADDRESSmyrealbox.com> contributed:

I'd replace with a pair of 6v golf car batteries in series.  More
capacity than most 12v combos.

Will Sill
"It's obvious to me that this country is rapidly dividing
itself into two camps _ the wimps and the warriors: The ones
who want to argue and assess and appease, and the ones who
want to carry this fight to our enemies and kill them before
they kill us. And in case you haven't figured it out,
I proudly belong to the latter."  US Sen Zell Miller (D)

HT,
Check out Walmarts store brand batteries.  I don't know who makes them
but there are only a few actual battery manufacturers.  They are
inexpensive and have a 1, 2 or 3 year guarantee.  Just take it to a
Walmart with the sales reciept and they'll give you a brand new one.  No
prorating age, etc.
I got stuck one night at camp Walmart when the chasis battery died.
Fifteen minutes later I was on the road.  That one failed about 3 weeks
later and another walmart just gave me a new one.  Turned out it wasn't
the battery's fault.  I had a voltage reg. problem.
I then put 2 of their deep cycle marine batteries in for the coach.
These are all heavy duty high amp hour ratings, etc.
We've been full-timing for over a year now.  We spent part of the winter
in S. Ontario and the rest in central NC.  Weather went from cold to
DAMNED cold.  We were snowed in several times at both ends.  I figure
we've also logged about 60 days dry camping during that time.  Heavy
duty use of furnaces, etc., all 12v and run off the batteries.  The
batteries have given me no problems at all.  
I figure between the price and the guarantee, you can't lose even if you
had to replace them after 3 years.
Oh yeah, when I returned the first battery they actually gave me a
refund and then rang up the replacement as a new sale so the guarantee
started over again.
There are Walmarts literally everywhere.  In the past, I've had trouble,
while traveling, finding a dealer for the same brand as a failed battery .  
Hope this helps
Speedy

I'd replace my two 225 Amp Hour 6v Trojan T-105s with the same thing.  
They are not sealed, but I add water only annually, and they've been
there since the 99 motorhome was new.  I do not discharge them below
12.10 volts, however, and changed the inverter to a three stage
Progressive Dynamics 9155 two years ago.

HTH,
Barrie B