Electric guitars are fun to collect. There are so many classic models, and new boutique builders are popping up all the time. The two primary characteristics are tone and playability. The biggest determining factor when it comes to tone is the pickups.
When it comes to pickups, there are two primary classic categories: single coil and humbuckers. Most pickups are constructed by wrapping wire around a magnet. When the guitar string vibrates, it induces the pickup to generate an electromagnetic signal. A single coil pickup has a well-defined tone but can be noisy and harsh at times. A humbucking pickup essentially combines two single coils in such a way to cancel out the noise. It also has a side effect of a more compressed, fuller sound, and often has a higher output.
I'd recommend having a selection of single coil and humbucking guitars. Here are my choices:
Humbuckers: Gibson SG
The SG is a classic, probably made most famous by Angus Young of AC/DC. It's a beautiful guitar, and it's a joy to play. It's slightly unbalanced (neck-heavy) but it's light overall. Gibson's 57 Classic humbucking pickups are on lots of your favorite records. For heavy music, an SG is often paired with a Marshall amp, but they sound amazing with Fenders and Vox's as well. Below is a video of me playing my 2004 '61 reissue with Lo Tom, through David Bazan's Benson Monarch combo amp on the "British" setting (more of a Vox amp vibe).
Single Coils: Telecaster
Tele's and Strats are the quintessential single coil guitars. I prefer Tele's for the most part. Telecasters excel in situations where the guitar needs to cut through the mix, and you're looking for either a clean sound, or something just slightly overdriven. You'll hear Telecasters in a lot of country music and indie rock from the 90's and early 2000's.
Below is a video of Mike Campbell showcasing his Fender Custom Shop Telecaster (the Telecaster was originally called the Broadcaster. Fender soon renamed it to sound more modern, due to the emergence of television).
P-90 (Single Coil): Les Paul Junior
The first Les Pauls had P-90's because humbuckers hadn't been invented yet. Gibson still makes a P-90 Les Paul called the Junior. P-90's are also single coil pickups, but they sound much different than Strat and Tele pickups. They are larger than most single coil pickups and bring way more growl and aggression to the tone. Mick Jones from the Clash is one of the most famous players of the Junior.
Here's a video of Doug and Pat comparing modern Juniors to more valuable vintage Juniors.
If you have these three guitars on your wall, you can really cover a lot of bases, and you can have a lot of fun.