I still prefer to hold a (physical) comic in my hand...but...you can't beat the convenience of digital books...especially the FREE ones:

Marvel.com | The Official Site for Marvel Movies, Characters, Comics, TV
http://marvel.com/digital_comics/list?isFree=1
Marvel.com is the official site of Marvel Entertainment! Browse official Marvel movies, characters, comics, TV shows, videos, & more.


I personally enjoy the older books in digital format...cleaner pages & crisper colors without the musty smell

Check'em Out.

Enjoy.