If your budget is on the low side and you're serious about learning to play, opt for sound quality over looks. So choose a vertical that stands tall. If you are in the market for a grand, length matters, but it requires space in your home. Japanese pianos, such as Kawai or Yamaha, are known for their dependable level of mid-range quality. Chickering, Baldwin, Knabe and numerous other makes can be extremely good with more individual variation.
Individual pianos have their own personalities too.
With older instruments, I often wonder if all those years of Chopin and Brahms have made them mellow. Even though a piano may be in good condition, old or new, it may not be a particularly good piano, regardless of price. A piano has ca. 10,000 parts under the hood. So when you find a piano you like, have a piano technician check it out for you before purchasing.