Higher end-Clarion, Alpine, Eclipse and Pioneer all make great stuff. No specific order. Used or own them all still.
Really Pioneer, Alpine, Eclipse and Clarion all make good stuff. I have not used a dvd HU so can not comment. I go for SQ units but thats what I am into. If you give more details about exactly what you want the HU to do then it would be way easier to give you options than listing 30 random good HU.
Some units I like but may not fit your specific purpose.
Alpine 9855, 9861, 9860
Eclipse CD5000, CD7000, 8454, 8455, 8053
Clarion 955MC, DRZ9255
Pioneer 980, 880