I went with Youi on my latest car due to pricing and being covered for modifications,etc. as long as everything is reported. Shannon's for someone my age (20 y/o male) was pretty expensive; almost double the 2nd most expensive quote I was given from another company.. and their cover was max $9000 agreed value (for a 94 JDM hardtop turbo!)
Previously I've always tried to go with Just Car however as they're closing down now, it's kinda hard for us young 'uns to get a good deal now!