1 Star - Reserved for the Worst of the Worst
2 Stars - Anime's that i've watched but didn't like (bad story / bad characters etc)
3 Stars - Standard Rating for Anime's i've watched 1-2 times and they were "okay"
4 Stars - Series that i've watched multiple times, with good Stories, strong Characters and strong re-watch Potential.
5 Stars - My Absolute Favourites, i've re-watched all of them, imo the Best Stories / Character Development / Artstyles out there (this doesn't necessarily mean they're in my Top 100, sometimes 4 Star Art-Style wins over 5 Star Story or the reverse)
Everything inbetween (1,5/2,5/3,5/4,5) i see as "Bonus" Ratings to certain Anime's (e.g Animation / Character Development / Outstanding Story bonuses)
If i start Watching an Anime, i'll 100% Finish it, i've never dropped an Anime.