Which lens should I get next?

Ckrol wrote:

The reason I would like another is lens is while the 28mm equivalent is my favorite focal length I need more versatility, what I'm wondering is if the 20mm is too close to the 14mm that I won't find it nearly as useful as the 45mm. I would consider a zoom but low light and depth of field are things that matter for me.

Hard task to advice. You prefer mostly primes. I have 14/2.5 -it was my 1-st prime for indoor use. Was O.K., but not optimal. 15/1.7 would be better.  For general street use both are too wide, especially for single person photos. My current "general use" prime is Oly 17/1.8. Interiors, landscapes, street in low light. I like this FL, very universal. But note, most of my photo in good light I do with a zoom.

In Your case however probably something longer than 17mm would be needed (as You have already 14mm and You like it). You're considering 20/1.7, but look also for Pana 25/1.7 -very good and very cheap. Unless You do portraits, I doubt 45/1.8 is most necessary. Definitely something from 17, 20, 25mm would be more frequently used.

There's also another possibility: buy first a cheap,used (second hand) kit zoom: Oly 14-42 or Pana 12-32. You may use them to check, which FL You need most and then buy the next prime. Note, that 12-32 is very small when collapsed, almost like Your 14/2.5. It may suit some part of Your needs for permanent use in future.

Regards,

-J.