I never lost my love of 45's and still actively seek them out. For starters, if you can find one that wasn't over loved, they boast a thick meaty sound. Most of them were mastered to sound good on less than hi-fi transistor radios. Play that same record back on modern equipment and the effect can be stunning.
Finding an older one in good shape is not that easy. This was before the era of balanced lightweight single play turntables. 45's were stacked on a spindle and played with tone arms made of heavy metals. They slid and grinded against each other. To top it off, the anti-skating mechanism was non existent, which caused unspeakable wear to the grooves as they approached the label.
In the USA, the 45 became a second class citizen. Not so much in the UK. The Beatles ( and individual members) and the Who put out standalone singles into the early 70's
Once the album took over, the 45 was relegated to presenting the potential hit single from the album. Here's where some of the fun started for me. Often times, the B-Side of the 45 was something that wasn't included on the album. Part of this fun of having rarities was taked down a notch with the inclusion of 'bonus tracks' on CD reissues. There are many that still remain uncompiled.
The punk movement signaled new life for the 45. Part of that rebellion was against corporate rock and overblown statements. The single proved to be a great outlet once again for two minute epics.
Below is a fairly recent b-side that remains uncompiled. The only place to get this one is on a 45.