In comic book collecting, there are no rules. Just get whatever you want to. Go raid a few dollar long boxes at your nearest comic book store and enjoy.
A few nerd guidelines on collectable books...
Ok...if you spot a comic book out in the wild that looks like it is in good shape and has a cover price of .25c or less...you might want to consider scooping that up.
Now the 90s books...
As time goes on, even with the massive runs, these books stand a good chance at being collectable over time.
As the next generation has less physical media presented to them, the experience of holding and reading an actual comic book will become a novelty.
Also, as the 90s kids venture into grey hair territory, the nostalgia factor of these books will be very real.
Now...the Holy Grail...

Find artists who are making their own comics and doing limited print runs of their work.
These stand a chance at being some of your most prized collector's items.

Have you checked on the price of a first edition...

1984 Teenage Mutant Ninja Turtles Tmnt 1 1st Printing lately?

Hey...happy hunting!

It has 8 GB!