I love browsing stationery, but rarely buy anything.
I spent some time testing out various pens when I started doing an accounting course that required me to handwrite various ledgers. My go-to pens had a hideous tendency to drop blots on the ledger paper.
A friend of mine had a selection of pens of various makes that he'd collected over the years, and he handed them over for my deliberations. I settled on a nice Parker (bottom of the line, so around $8 each, if I recall - but a distinct step up from the black finetip Papermate pens that I bought for $10 a box), and I buy an extra every so often.
I put together a writer's kit for my sister for her birthday - a Parker, a wooden box full of slips with writing prompts on it, a Staples-brand little notebook with a matching pen slipped through the loop on the binding, and (I think) a larger notebook as well. I bought a mini-notebook and pen for myself at the same time, and it has seen so much use this year - it fits nicely in my purse or my knitting bag, so grocery lists and tracking the rows on the current knitting pattern both happen inside. Sadly, the binding isn't wonderful: pages have come loose, and I've had to reinforce the loop for the pen. It's been worth the dollar I spent on it, though...
One of the benefits of this workplace is that we have a big supply shelf in the mailroom, and we can help ourselves to whatever we need. As a result, I've tried out a few pens new to me, and have become rather fond of a black rollerball pen. I'd specify make and model, but in order to keep it at my desk, I ended up taping a fake daffodil to the top of the pen so that no one could possibly mistake it for his/her own and walk away with it. The tape obscures all the writing on the clip except G-2. On the plus side, I was able to keep track of the pen long enough to run it dry, then start on a second (also daffodil-bedizened).
The standard notebook on the supply shelf is 7.75x5", coil bound, green paper (narrow ruled with blue lines), 70 pages, and I've grown rather fond of that as well. I don't think I'd buy one for personal use, though - it's too strongly associated with work.