It's pretty much up to you, unless you have the currency for some insane rare bow, then you could always go with Lioneye's or Chin Sol. Both are very affordable and easy to build around. Either of those will be able to clear all of the content in the game with the right build and experience with the playstyle. For more guides on build, you can visit - https://www.u4gm.com/

In general, i'd say Windripper is the "best" unique bow currently, as I assume we're not talking about high end rares / mirror tier weapons etc. Windripper can be used as a main weapon for a high end boss killer / mapper, or it can be used to MF.

Lioneyes Glare and Death's Opus are the next best options. Lioneye's is probably the better overall bow, but Ice Shot tends to be much more successful when using chain rather than pierce as your QOL clearspeed mechanic. However, If you want to go chain then there's really no reason to be anything other than Deadeye, and if you're going Deadeye then the perfect accuracy and far shot on Lioneye's is more or less wasted, making Opus much more appealing by comparison.

Also, if you're going Deadeye as opposed to raider for instance, then you'd want to be able to maintain and generate Frenzy charges on demand so the free +2 proj from Opus helps avoid using GMP or LMP to support Frenzy. And get cheap POE Currency buy from us.