I would say depending on the budget preferably a speaker you can try before you buy, has good reviews, and is not fussy about room placement. Make sure to choose a size that is suitable for your room size and will likely have synergy with your amp. If your amp is on the warm side, probably best not to get warm sounding speaker and vice versa.
Make sure room acoustics are decent before auditioning. Any speaker won't sound great in a poor sounding room.
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