I recommend getting both because they have their differences. I don’t care what anyone says, both DOA5 and DOA6 are the best playing Dead or Alive games.
Both are very good, unique and underrated fighters. I think most people who hate the games never really took the time out to truly understand the mechanics. DOA6 has better graphics and imo plays slightly better, but since DOA5:LR is older, it has more content like characters and costumes. Try out the free Core fighter versions on the PSN store to see if you like it. Yeah, the DLC is ridiculous, but in all honesty, most fighters nowadays have too much or overpriced DLC in general.
Of course there’s Tekken 7, but I think the DOA games are different experiences from Tekken and it reminds me more of Virtua Fighter. Then again, it isn’t like there are many choices with 3D fighters, so the pickings are diminutive unfortunately.