Haha, Mono, don't listen to them!
Each game has its different strengths.
You'll like the first for all the new and fleshed out world, species and characters.
You'll love learning your old and new teammates better and care about them in the second. Also, Illusive Man is boss. The ending will get you choked up for all you've been through.
You'll be amazed at the scope events unfold in the third one. Whether you'll be satisfied with the ending should be left to yourself with an untouched opinion, don't let anyone get in your head.
Finally, you'll remember the way, the adventures and the friends you found and lost throughout more than 60 hours, not the last 10 minutes.
Enjoy the trilogy, don't let people focus you on the bad stuff.[/SPOILER]