Author has written 39 stories for Justice League, Teen Titans, Transformers/Beast Wars, Due South, X-Men: Evolution, Cowboy Bebop, Half-Life, Dragon Ball Z, Doctor Who, and Flash.
Justice League (these all operate under the rule that Teen Titans is in continuity with the DCAU):
'In the Spirit', 'Tis the Season' & 'All Star Justice League' are part of the above continuity family and have references to each other dotted around, but nothing major.
'Priorities' works with or without all the above continuity.
'Legacies' was my first stab at a DCAU Reverse Flash story, and for a variety of reasons I didn't like it and did it again in 'Complicated Simplicity' - because of when it was written, it contains some references to 'First Steps'. For the sake of completeness, here it is!
'New Shoes' isn't linked to anything, and assumes that Teen Titans isn't in continuity with the DCAU.
The rest of the Who stories can be understood independent of each other.
The Black Mesa Incident (novelization of Half-Life, Opposing Force & Blue Shift)
Well. That all felt a bit nerdy. Gloriously so.