My fridge is always full of 160NC. Since I'm printing in darkroom slide film doesn't make sense and I'm not convince with the results I had with fuji yet. Portra rocks!

B&W: Pan F+ [slow] Tri-x, or T-Max 3200

I love Reala.

I've been getting into film in the last few months and it's going to be pretty hard to go back to digital now! Something about the feel of film & the whole process that just seems so much more real than digital. Plus it's a lot easier carrying around a rangefinder than a big dSLR when I'm out exploring.

Favourite films so far would be:

Portra 160/400 NC/VC depending on what/where I'm shooting
Astia
Tri-x
Neopan 1600

I've been shooting mostly Ilford FP4+ in 4x5 rated and developed at ASA-100 instead of 125 (makes it easier to meter).
Occasionally I'll use a sheet of Ektachrome 100G.

For 135 my favourite B&W film in good light is Pan-F+ at ASA 50, but for low-light I use TMAX 100 for it's low reciprocity failure, unfortunately nothing from Ilford comes close to it's performance for exposures in the several-minute range.
For colour I really like Kodachrome 64, but I've gotten good results from Fujichome 400 in low light. I've used Velvia 100f and Velvia 50 but I prefer the lower saturation of 100f for general-purpose shooting. Tried Provia 100f and it was a little too blue for me. Overall I'm unimpressed with how Fujichome handles pastels, which is why I tend to go for warmertone Kodak emulsions (Kodachrome in particular excels at reproducing muted pastels while still giving strong contrast)

In 120 I love Ektar 100, but it isn't available for 4x5. I'll likely shoot fuji 160s for 4x5. Trying some tmax100 now and am learning to home
develop.

For B&W it's Tri-X in HC-110- Fuji Neopan SS I like also

For color once and a while I will spring for some Velvia 100 but its usually some expired rolls of whatever I picked up on Ebay for super cheap