LoL imo is much more tactical. DotA games were often about that Ursa getting a couple of kills and going on to trample the entire team.
There was no coming back from mistakes.
In LoL, I've had more times than I can count where my team managed to pull off a fast baron or kill a lone champ to turn the entire game around.
There are also a lot more interesting tricks you can do in LoL than you ever could in DotA, like jumping/teleporting to wards etc.
DotA had some engaging stuff too, but it was a mod to a larger game and it was limited by that.
LoL is a much more engaging game for me, the only downside being the mouthbreathers in the community which hinder actually good players, but you had your fair share of idiots in DotA too.