Thats a tough question. I would probably say Louis Vuitton just because they have such a big variety of products. You can get everything from a cosmetic pouch to satchels, totes and luggage.
For me it's the LV monogram Never Full bag...it's just such a staple and I know it'll never go out of style. I've had mine for 5 years and it still looks brand new! This might be bc I use a purse hanger so it never touches the ground (also good luck I'm told).
If any of you want to keep your bags looking like new I may suggest www.THEHOOKUP.com for a purse hanger. I have all 3 finishes and am always getting complimetns on them!
Although I love my Chanels, I always seem to reach for my Balenciagas for every day use. Those bags seem to go with any outfit I wear, work or casual. Definitely Balenciaga