1) All expenses paid 2) Appreciative 3) Complemental 4) Costless 5) Encomiastic 6) Eulogistic 7) Favourable 8) Free 9) Gratis 10) Laudatory 11) Panegyric 12) Panegyrical 13) Positive 14) Praiseful 15) Praising 16) Unpaid 1) Costing nothing 2) Costless 3) Encomiastic 4) Eulogistic 5) Favorable 6) Favourable 7) Flattering 8) Free 9) Given free 10) Laudatory 11) Panegyric 12) Panegyrical 13) Praiseful 14) Praising 15) Scot-free 
• (a.) Expressive of regard or praise; of the nature of, or containing, a compliment; as, a complimentary remark; a complimentary ticket.
Com`pli·men'ta·ry adjective Expressive of regard or praise; of the nature of, or containing, a compliment; as, a complimentary remark; a complimentary ticket. ' Complimentary addresses.' Prescott. 
[adj] - costing nothing 2. [adj] - conveying or resembling a compliment
costless adjective costing nothing; `complimentary tickets`; `free admission`