What to upgrade to?

Zu Audio speakers like Druid mk6 are high efficient (101db) and does not require high power amp, they are reasonably priced with full refund/return guaranteed withing USA. Low power amp (tube or SS) and it can match your budged even if you will buy new turntable too.

You forgot to say what you got now ?

Chakster,
Thanks for your reply. I have looked at Zu and my amp would work perfectly. Btw I purposely didn't list my table or speakers because they both are excellent. I just would like to hear other people's take on which made better sense to upgrade. Some say source is #1 others argue speakers make the biggest difference. Thanks for your recommendation.

You're welcome. It's definitely worth to try ZU and simply return them with no loss if you don't like it. 

Speakers definitely will make bigger difference if your turntable/cartridge/tonearm already very nice.

When i upgraded from traditional (2way) Dynaudio speakers to Zu Audio Druid mk4 i was shocked. Because ZU is different concept, their own driver is super efficient, this is full range driver, NO CROSSOVER, only high pass filter for super tweeter. This is the most dynamic system i ever heard and it's a pleasure to use Zu Druid even on very low volume (if needed). Also my power amp right now is Yamamoto A-08s with 45 tubes (only 2W power) and preamp is passive Pass Aleph L. It's so easy to drive ZU Audio Speakers even with 2w amp in relatively big room! Amazing. 

Try it. maybe you will discover something completely new if your current speakers are not full range type. 

If you like it you can always add Zu Audio SUB, there are few excellent models look here. 

Another speakers that impressed me were Tannoy.