Good points about the Unicode and datetimeoffset (I've never personally used that data type):

-- list column data type, including len(s), if applicable

CASE WHEN c.is_computed = 1 THEN 'AS ' +

(SELECT definition FROM sys.computed_columns cc WHERE cc.object_id = c.object_id AND cc.column_id = c.column_id) +

CASE WHEN c.is_nullable = 0 THEN ' NOT NULL' ELSE '' END

ELSE t.name + CASE

WHEN t.name LIKE '%n%char%' THEN

'(' + CASE WHEN c.max_length = -1 THEN 'MAX' ELSE CAST(c.max_length / 2 AS varchar(10)) + ')' END

WHEN t.name LIKE '%bin%' OR t.name LIKE '%char%' THEN

'(' + CASE WHEN c.max_length = -1 THEN 'MAX' ELSE CAST(c.max_length AS varchar(10)) + ')' END

WHEN t.name IN ('datetime2', 'time', 'timeoffset') THEN

'(' + CAST(c.scale AS varchar(3)) + ')'

WHEN t.name IN ('decimal', 'numeric') THEN

'(' + CAST(c.precision AS varchar(3)) + ', ' + CAST(c.scale AS varchar(3)) + ')'

WHEN t.name IN ('float', 'real') THEN

'(' + CAST(c.precision AS varchar(3)) + ')'

ELSE '' END +

CASE WHEN c.is_nullable = 0 THEN ' NOT' ELSE '' END + ' NULL'

END