Well this is my list of Top 10 anime ova's. Technically based on a handful of ova's I've watched so far. On-gong's of just 1 eps released ain't included. Bet you're hoping for Gundam Unicorn lol.
10) I"s Pure ~ Typical generic storyline but somehow this ova seems to caught my attention. Worth watching in my opinion.
9) Sōkyū no Fafner: RIGHT OF LEFT ~ Trust me, this anime is just painful. The plot is nice, action is decent but then again there's just this one particular detail that you need to shoulder in mind throughout, eventually everyone will ***. Just watch it and you'll know what I'm implying.
8) Voices of a Distant Star ~ Makoto Shinkai's first ova is definitely his best. A simple complete storyline that truly gave the audience a lasting impression. His other two works are indeed superb, yet twisted plots, rush endings seem to be the main flaw and setback for any anime.
7) Kowarekake no Orgel ~ Wow I love this one. Beautiful, moe, simple and a nice theme song that harmonizes with the anime. Truly remarkable.
6) Karas ~ If you love Mask rider / Kamen rider, then this is a series just for you. Nice battle scenes for this six part ova in cell-shade.
5) Hanbun no Tsuki ga Noboru Sora ~ Why is this here with mediocre art and normal plot? Well it's really good. Despite what was stated, give this one a shot and you'll know why i said so.
4) Oh My Goddess! ~ The very first ova series that I've watched. Belldandy FTW.
3) Mobile Suit Gundam: The 08th MS Team ~ The best gundam series from my pov. Shiro Amada - not an ace pilot, not trained to be a killing machine, no seed mode, nothing. He's just only human lol. But thats the best thing, a main character that's actually vulnerable and it takes him to utilize his wits and guts to get out of all the predicaments. This is also the first series that I admired a Gouf so much. Norris Packard a true ace FTW.
2) Macross Zero ~ Hands down the best macross series ever. Stunning visuals, in-dept storyline, luscious background sceneries, well rounded characters, Fockor, more Fockor, 4 types of romances between characters evident to the audience. Mayan Song. Truly an aspiring anime.
1) Hellsing ultimate ~ Yup I love this so much. The story is epic, top notch gun penetration scenes, more blood, more gore and more Waffen-SS of the Letzte Battalion. The protagonist is just so badass, you'll piss in yer pants once he activates Cromwell release. A hero of an anti-hero rocks.