Do you need an analog connection? Analog video connections have all but disappeared from Blu-ray players. Bowing to pressure from Hollywood, no player since 2011 has been able to send HD via their analog component video port, and, most makers have now removed those connections altogether. Many lower-end players lack analog audio connections, even basic two-channel (stereo) connections.
Do you have an HDTV? For the best viewing, you'll need an HDTV with 1080p resolution. Some HDTVs only have 720p resolution, and with those, the HD images will be scaled down to fit the television's available pixels. However, the image is still HD, and picture quality should be terrific. If you don't have an HDTV, save your money and buy a DVD player, as a Blu-ray player's higher-quality image output won't be visible on a standard-definition television.
Do you want to watch movies in 3D? For 3D viewing, you'll need a Blu-ray player capable of 3D output, a TV capable of displaying 3D images, and a pair of 3D glasses for each person.
Does your other home theater hardware include streaming Internet apps? One way Blu-ray players differentiate themselves is with their selection of Internet-enabled apps. If you already own home theater equipment with Internet capabilities -- such as a smart TV, a media streamer like the Roku box or a gaming console like the Xbox 360 -- then the streaming offerings will mean less to you.
Do you want to use the Blu-ray player to stream music, movies and pictures from your PC to your TV? If so, be sure to select a Blu-ray player with DLNA compatibility (most players that offer streaming features qualify). Again, your other home theater gear may already have DLNA functionality built in.
How will you connect the Blu-ray player to the Internet? Wi-Fi helps to get to all of that streaming content in case you don't have a convenient wired (Ethernet) connection. Many Blu-ray players now have Wi-Fi built in. Others will include a USB Wi-Fi adapter in the box. The least expensive choices might only be Wi-Fi ready -- which means you'll need to purchase a separate Wi-Fi adapter if you need to use Wi-Fi to connect to the Internet -- or might not offer a way to add Wi-Fi at all.
Do you have a lot of DVDs? Blu-ray players can also play standard-definition discs, but some do a better job of it than others. That's something to consider if you own a large collection of standard-definition DVDs.