I’m a big fan of Pilot’s original B2P gel pen made from recycled plastic to resemble plastic water bottles. They look great, write fairly well and are very comfortable in the hand. The Pilot B2P is part of the Pilot Begreen Range of recycled pens.
The design changed a bit when Pilot began making a ballpoint version of the B2P incorporating a bubbly, fluted barrel meant to evoke a bottle of sparkling water.
And now, Pilot’s come out with a jazzier model called the B2P Soda ballpoint pen, sold primarily in Europe.