Sola, Angel Beats! Recommendations
Both Anime have simular art style. Both slowly build up to a climax.
Both stories involve two girls (one being a silent type girl) revolving around the life of one boy with a mysterious past.
Both have a feel to them of tragedy and wanting to find something again or do something they could not do before.
Both of those series possess a tragedy ending, and both deal at some point about hospitalization. While Angel Beats deals with the replacing of an heart, Sola deals with one of the main characters in an hospital.
I know you love watching tragic romance if you've watched "Angel Beats". So I'll recommend you to watch "Sola". Both anime tells the meaning of love, friendship, and the hardship between life and death. :D