I've got accounts at Vanguard, Fido, and Schwab.
I inherited an IRA at Vanguard, as well as 529's that my dad had started for my sons. Vanguard is great for low costs and fine for DIY... but they SUCK when someone dies. They lost multiple copies of the death certificates... could not communicate between the brokerage side and the 529 side so seperate processes/paperwork/death certificates had to be sent. (Oh - and both sides - brokerage and 529 lost MULTIPLE copies of the paperwork and death certs... We burned through a LOT of certified death certificates before they finally completed the transfers.)
But - while you're living, they're great if you don't mind DIY.
My dad also had schwab - and the death /transfer to beneficiary was seamless. My sister ended up transferring 100% of her share to schwab just because of customer service.
Fido - I've got one older IRA there - they have a good calculator (Retirement Income Planner) that I like - so I'll leave that decent performing IRA there so I can use the calculator.
I just rolled over a work IRA and debated between the three - I ended up choosing schwab. They all have their advantages and disadvantages... I guess I went with Schwab because it was easiest to roll it to them.