MTG Salvation

Thanks so much for your help! I really appreciate the responses.

Hey Everyone - I recently acquired an Aether Revolt booster box in trade with my hobby comic business; which has rekindled my my desire to collect after a rather extended absence. Given the evolution of the game over the past couple decades, I am trying to find a good place to plant my feet to begin building a solid collection and hoped for some advise. I am mostly interested in quality over quantity (i.e. cards that are likely to retain some value and liquidity). As a finance professional, it pains me to see the term 'investment' thrown around with collectibles, but I can rationalize a bigger budget if I have some confidence that the cards are not going to devalue aggressively. I probably won't be playing with paper cards, so I am not restricting myself to the most recent sets. So I guess I am asking the community: If you were trying to build a small, but impressive collection, what sets and cards make up the upper echelon of MTG (notwithstanding the Power 9...)?