Yes, right from starting university in 2005 – I wasn't sure what system to buy, but a friend who was using it said, "Nikon is the best, especially the lenses", so I went for it and I love it. I saved hard for my D3S and I've had it for years, then more recently I bought the D810 for its resolution. I'd love to have the new D850 for its combination of resolution and power!
I mostly use the 50mm f/1.4 and, if I have the space to step back, the 85mm f/1.8. I also sometimes use the 35mm f/1.2.
I also love using my Nikon F100 – my boyfriend bought it for me and I shoot most of my diary work on it, using my prime lenses. I love the grain and tone of film and the surprise element of not knowing what you've captured until you have the film developed. It somehow feels more special. My diary shots aren't planned so it doesn't really matter if they don't turn out – it's just the cost of film that is the issue. I buy the cheapest colour film can find on eBay, I never shoot in black and white principally because I love colour, its different tones and especially skin tones. I love skin – I'm a big fan of the work of the painters, Lucian Freud and Jenny Saville, so colour is very important to me.