I would tell them #4.

I would also take a week off between jobs. I haven't done this often, but its a great palate cleanser.

#4

As close to 2 weeks before your start state as is practical.
I've seen even simple security clearance and background checks take much longer than anticipated. If it's outside of your "2 weeks to start", simply negotiate a new start date if the new employer cannot accommodate your start before these clear (which is often the case). It will be up to you to monitor.
Make sure you have written offer signed, full contract back, and all clearances before giving notice. Even if you think it's all fine, these are things that can delay you and keep you without income.

2 weeks prior to your start date, which will also presumably be after you sign the documents. Definitely don't do anything until you have both signed the written offer.

I would do 2 weeks before start date. Old company might let you go once you without 2 weeks, new company might rescind your offer.

I would not do ANYTHING until you have a written offer, and if there are any contingencies (background/credit check etc), wait until those clear. Then, if you need the money and can't afford a gap in empployment, do 2 weeks before your new start date. Regardless, you should always be prepared that they let you go before your preferred end date. GL!

I just got a job offer which I verbally accepted over the phone but I wouldn't start until mid-November. I was told i would get an offer letter via email and that i needed to countersign to accept. Should i give my 2-week's notice:

1) now for me leaving mid-nov since I verbally accepted over the phone
2) when I get the written offer letter
3) when I submit my countersignature and fill out paperwork for the new job
4) 2 weeks prior to my start date

Your thoughts to help me decide? I am leaning towards #3, but may wait for item #4 if item #3 is only a day or two earlier so I don't have a gap in jobs since I need the money.