25 and I haven't found my holy grail yet.
Here's my current racquet inventory:
4 Yonex RDX500 MP (2 for sale)
3 Yonex RDS 001 MP (1 for sale)
1 Yonex RQ7 (For sale)
1 Babolat Aero Storm Tour
1 Babolat Aero Pro Drive Standard (demoing now and probably will result in a purchase)
Past racquets:
2 Babolat Aero Strike Cortex
1 Babolat Aero Pro Drive + Cortex
I don't have a string setup that I always use as I like to switch and try new things, but here's everything I've tried so far.
Babolat Pro Hurricane Tour 17
Babolat Pro hurricane Tour 16
Babolat Xcel Premium
Babolat Attraction
Babolat Speed something...
Babolat Razor something...
Babolat Ballistic
Luxilon Big Banger ACE
Luxilon Big Banger
Luxilon ALU
Head Ultra Tour 17
Toalson Ichiban
Yonex Tour Super 850
If my body could afford it, I'd string only with Pro Hurricane Tour 17. Since my wrist hurts, I've found that Pro Hurricane Tour 16 and Xcel Premium is the best so far, followed closely by the cheaper Head Ultra Tour 17 and Yonex Tour Super 850 setup. However, both should lose tension and feel by the third week. I know I will never use Toalson Ichiban or Babolat Ballistic again since I did not like any aspect of them. I would try Luxilon again if the prices drop even though I didn't find anything spectacular about them.
I plan to start a racquet collection as it has quickly become a hobby. We'll see how that turns out.
I also keep and label small pieces of every string I've ever tried.