So I start a super new job in a few weeks! I've not worked since dc2 was born 5 years ago. It's an office based job, but will be traveling by train. Needs to be fairly large as will be using it for laptop as well. Not in every day so it will be with me all time.
I use a big Marc Jacobs bag (it was $75 here in NYC) which has side pockets for my water and coffee. Full price it's way too expensive but do a Google to see if it's discounted or available 2nd hand on eBay. This is the one I have.
Another good place to look is Knomo. The nylon laptop bag is nice. I prefer nylon to leather because I don't like the weight of the leather bag once I've got my laptop in it.
Don't get a backpack if you can avoid it. They never sit right and are a pain if using public transport as you are taking it on/off all the time.
When my youngest is no longer smearing me in peanut butter on an almost daily basis I will buy this bag. It's extremely versatile but at $425 I'm waiting. My Marc Jacobs bag has been washed in the machine a few times now.
I use a Vince Camuto leather bucket bag (can't find pics online as it's a couple of years old now). It fits my laptop in (the end does stick out a little), plus cables, portable conference pod, A5 writing folder, umbrella, purse, phones, etc. It holds a LOT but looks great and I still get compliments from people about it. It still looks as good as new after being used for work every day for several years. I'd definitely look at Vince Camuto bags if you want a normal shoulder bag that doesn't look too "corporate".
Congratulations on the fab new job! Here's some criteria I used when I picked my bag (also used for work and home): 1. Neutral colour 2. Washable or wipeable 3. Pockets: I wanted an upright water bottle pocket and an outside pocket for tickets etc 4. Sized right: fits laptop, cord, notebook OR spare kid clothes and a nappy 5. Safe: zipper closure 6. Comfy and hangable when you're in the loo or changing a nappy, i.e. 2 short handles and a long strap
I usually head to TK Maxx or an outlet village. Tumi does nice backpacks which might work if you have coat pockets for the things you want handy.