[mithrilG60]

Either Napoleon or Weber. Both are equivalent in level of build quality, warranty and pricing. Personally I've had a Napoleon Prestige P450RB w/o side burner for the last 6 years and it's been phenomenal. We cook almost exclusively on the grill in the summer so it's gotten very heavy use in that time, the only part that's worn out is the sliding drip tray and that was just because I didn't clean in out as often as I should have.

Regarding gas use, any quality grill should be well insulated and act effectively as an oven with the result being very little fuel required to maintain cooking temperatures once the grill is up to temp. I'll typically see 3+ weeks on a standard 20lb tank from my Napoleon and that's with cooking at least 5 nights a week on it including at least one roast or rotisserie per week.

It's the el cheapo $300 - $400 BBQ's from Costco et al that chew through the gas, especially if you're trying to cook roasts or use the rotisserie. Those grills are also much more challenging to use and consistently produce moist results on as they are much harder to do proper indirect grilling on due to their inability to properly hold heat with the burners off or on low.