I generally use Ilford's MG IV RC for quick stuff. A couple of years ago a store had a sale of them and I nabbed 2 boxes of 10x100 8x10 for about $450! It is a generally good paper as RC's goes. I also have 3 boxes of 100 sheet of Agfa RC, Like the blacks a bit better in that.
For fiber based stuff, generally Oriental, but also Ilford MG IV for a warmer tone. Still have some Ilford Warm Tone 11x14 left too.
I always buy paper when I see it for sale. I even have a 500 sheet box of Agfa #6 (8x10 SW) - it is getting on in age, but still works as a "hail mary" paper for those blown negatives. Call it Art and you can get away with it.
The more exotic stuff, Forte, Berger, Kentmere, etc is not available here on a regular basis so I tend to avoid them. Nothing worse than running out of a paper emulsion that you just have gotten to work for you and hearing "Sorry, don't stock that anymore".